Like the title suggests, what should I look at to improve fuel economy?

I've been monitoring the fuel economy of the car since I bought it, and its always been around the 13L/100km mark, which isn't great, but it wasn't too bad either. Now I've worked out my economy that I've got out of the most recent tank, which mind you has lasted me the last 2 and half weeks because I haven't been out and about much in it, but its currently sitting around 20L/100km, which is bloody ridiculous if you ask me.

I know this tank has been all local driving, and its spend a bit of time in traffic crawling around, but to do 230km on an indicated 3/4 of a tank? cmon... :doubt:

I know theres the o2 sensor that will cause issues if its malfunctioning, but surely it wouldn't be this bad if theres only that that needs replacing. I haven't been driving it with a heavy foot either, on occasion it'll get booted a bit, but say 95% of the driving involves the auto box shifting around 2300-2800RPM.

If I'm honest I'm getting sick of the Verada, may only be little problems, but its all adding up...

Any advice or hints are appreciated, Thanks.

short trips around town will kill your econ.
esp if its cold in the mornings but the choke will be working hard to bring the engine temp up fast by burning additional fuel to reach operating temp fast.

needlessly using the aircon - like if its warm but not hot, wind a window down IMO
IMO the climate control isnt the best for running around town on short trips only good for highway temp maintanence.

have you run a bottle of injector cleaner thru the tank?
that might help?
it did in my car, econ improved about 1l/100km :)


also - has it been serviced on time?
i found that when (mine at least) has just been serviced, for the next couple of weeks its very efficient :)

just a couple of ideas.

tyres make a big difference i had pirelli dragons in 245/35/19 and i got 550kms on a tank, but then i got cheap tyres (antyre) and got 600kms/ tank but they didn't grip AL ALL and they squealed and were really noisy. so i went back to pirellis and it fropped back to 550 / tank. same tyre pressure and size! but there really grippy and quiet.

Incorrect tyre pressures
Excess weight carried in car
Driving at higher speeds with windows down\roof racks on
A poorly stacked load on the roof racks
Air con use
Dirty\Clogged air filter
Dirty fuel
Short trips
Sudden acceleration - as opposed to gradual and smooth

Thats generally what causes poor fuel economy but I doubt that any of those apply to you, save for the last two :D What fuel do you use in your car and have you tried switching brands?

Thanks for the prompt replies guys, I'll try and go in order.

Air con has been off this whole tank, occasionally the fan is on, but I'm more the type to put the window down a tad than turn the fan on anyway.

Haven't run any sort of injector cleaner, tbh never heard of it lol

Its due for a service now, but as I've been out of work for the last 2 weeks, no money to get it done with. Its on the list of things to do.

Its on the factory 16" alloys, wrapped in Sumitomo HRT H4's that were new on the car when I bought it, but don't grip nearly as well as I think they should especially in the wet, so I don't think they're causing an issue. Running at 36 Psi.

Weight wise it hasn't changed since the sub went in, unless you count the tool kit thats in the boot now, which weighs all of 1kg maybe lol

Since I bought it I've always run it on Shell Regular Unleaded, usually from the same couple of servo's too near home. I'm stumped if its the fuel, don't really want to run it on Premium though, shouldn't really benefit from it at all technically.

Its one of those problems where it can be a number of things.
The very first thing I would do (actually did it last week) is to change the o2 sensor, this is really not all that expensive. I purchased mine off Ebay for $55 incl. postage, and its a brand new FACTORY part (the seller is in Adelaide so I presume its an ex-mitsubishi employee).
You can try to fit it yourself but it really is a bitch, it cost me $60 for a mechanic to do it.
Total: $115

-Other things that can effect your consumption is the airfilter (replace if dirty, or buy a K'n'N...well worth it),

-Shot plugs,

-Gunked up oil (a good kero rinse when changing the oil will clear this up, use SEARCH for this procedure),

-Possibly the AFM might be on its way out but you would notice this because the car would run a bit rough.

-Auto transmission might need a service (just a thought, I don't drive one)




Did the jump in fuel consumption happen suddenly or did it slowly creep up?
I've never had 20L/100kms before, not even on a track day.

Thanks AFA82, few good points you've made that I didn't think of. I didn't think the o2 sensor would be too bad, from what ive heard it should cost me more than $150 to have done by a mechanic anyway, probably just have them get the part, saves my effort lol.

Haven't actually even checked the air filter, probably a good idea to have a look at it haha. If the plugs were shot wouldn't that effect start up etc? I'm having no issues there.

When it gets serviced I'll make sure its a thorough oil change, want it done properly. Whats an AFM? Car hasn't be running rough though, so nothing to worry about?

Auto tranny definitely needs a service, Boozer checked the tranny oil for me the other night and its black (supposed to be pink?) so I'm thinking it needs a good flushing, just another one of those things I have to put off until I've got an income again.

The bad economy has come out of nowhere, it was around 13L/100km last tank, and its been like that for a fair while, this 20L/100km has come out of no where.

The bad economy has come out of nowhere, it was around 13L/100km last tank, and its been like that for a fair while, this 20L/100km has come out of no where.

That's pretty good evidence for the oxygen sensor being shot.

You could also try raising your tyre pressures to 40psi; it'll ride a bit harder, but apparently it's worth a little bit in saving fuel.

Must agree sounds like O2 sensor. If you cant afford to do this at a minimum do the service on the auto if its black. It could cost you heaps if it fails.
Regards

This consumption is ridiculous!

20L/100 is petrol landcruiser usage...

Give the car a major service including o2 sensor, up your tyre pressures and go easy on the loud pedal.

If nothing changes, torch it!

My 3L auto uses 9.3/100 70% freeway 30% town.

Remember, litres used (when filling up at the pump) divided by total km's traveled multiplied by 100 will tell you exactly how much on average you used.

And what I have learnt is that the 1/4 mark on the petrol tank isnt really 1/4 tank, its more.

And what I have learnt is that the 1/4 mark on the petrol tank isnt really 1/4 tank, its more.

EDIT: whoops

Yeah the condition of the transmission fluids is worrying me a bit at the moment, It'll be done as soon as it can be. As soon as I've got an income again I'll book it in for a major service with all this stuff listed. Hopefully won't be more than a few weeks away, I can't afford to run a car thats using the same amount of fuel as a V12 Aston at the moment lol

I too have noticed the bottom 1/4 isnt exactly 1/4 of a tank, much like the top half is much more than the bottom half. This is why I based my calculations on 45L of fuel used and not 53L, which is what it'd be if they were perfect quarters.

If you want to get the o2 sensor done, and you want to save a bit of money, then you can't go by atleast checking Ebay if this bloke is still selling original ones. You get it delivered to your front door for $55. No mechanic in the world is going to hunt one down off the net, they are just going to call the nearest parts centre and slap you with $150+ just for the sensor.

Anyway, it sounds like the o2 sensor because of the sudden fuel consumption issue.
The Air Flow Meter was just a thought but that probably isn't it.
As for the spark plugs, it wouldn't really effect start up but it definetly effects all round performance.


Oh and a clean airfilter is a must!

tyres make a big difference i had pirelli dragons in 245/35/19 and i got 550kms on a tank, but then i got cheap tyres (antyre) and got 600kms/ tank but they didn't grip AL ALL and they squealed and were really noisy. so i went back to pirellis and it fropped back to 550 / tank. same tyre pressure and size! but there really grippy and quiet.

Stay the hell away from antyres. I currently have 2 on the back, they do not hold air, eg fronts are at 30psi instead of 38 after a while, one rear was at 13, the other on 17. Not to mention they have 0 grip. I can spin a wheel with 25% throttle when its wet at 50kph+.

just a note for you to remember, you have also disconnect your battery a few times, so your ECU is still learning...you tend to use a bit more fuel after your ECU has been reset. it will settle down eventually. If that doesn't happen then check the other stuff that other meembers have suggested.

This consumption is ridiculous!

20L/100 is petrol landcruiser usage...

Give the car a major service including o2 sensor, up your tyre pressures and go easy on the loud pedal.

If nothing changes, torch it!

My 3L auto uses 9.3/100 70% freeway 30% town.

Remember, litres used (when filling up at the pump) divided by total km's traveled multiplied by 100 will tell you exactly how much on average you used.

i got 8.8L today on that similar 70% freeway and 30% town according to the trip computer... ;)

i got 8.8L today on that similar 70% freeway and 30% town according to the trip computer... ;)


Are you saying that it stayed at 8.8L while doing both freeway and town?

Probably not, my calculations are based on an average of combined driving.

Are you saying that it stayed at 8.8L while doing both freeway and town?

Probably not, my calculations are based on an average of combined driving.

off course it a based on an average combined driving, otherwise i can give you my instant readings and they can vary from 0.1L/100km - 60+L/100km

just a note for you to remember, you have also disconnect your battery a few times, so your ECU is still learning...you tend to use a bit more fuel after your ECU has been reset. it will settle down eventually. If that doesn't happen then check the other stuff that other meembers have suggested.

I found my car used less fuel after I reset the ecu.
Maybe it had to unlearn some bad habits from the previous owner.

Yeah I reckon an ECU reset could help economy, if you "train" it to upshift sooner and all that.

I recently ran my gauge to empty with the light flashing, 510kms driven, and still had 11L in the tank. Basically, the fuel gauge is a bit of a :liar:

if you want to try a good injector cleaner..

Nulon Total fuel system cleaner.. it's in a silver bottle.. about $22 for a bottle.. but i can vouch for it.. even a group of my mates who are all mechanics (some hold toyota master tech qualifications) voice for this stuff..

if you have the money to, at least drop the oil and change the filter yourself.

i did mine (well i stood around and watched my dad do it for me hehe) the other week, and almost instantly i got better fuel econ - instead of my 'normal' 12.4/100km around town, im getting 10.8L/100km avg's
my car also is reving at lower RPM than before as well, by about 200rpm or more when driving at highway speeds (of the legal nature)

For 50bucks its pretty easy to change the oil and filter yourself..
(i cant say what oil i put in, just Shell in a yellow bottle!!! haha)

(saying that tho, i do know what its like to have no income and have an expensive car to run around in..)

Dirty / shot spark plugs will effect startup too - along with fuel econ and general driving...
without good clean spark, there is (not as) clean fuel burn, which often results in more fuel being injected to be burnt coz the computer thinks its running lean...

Believe it or not, it actually appears to have sorted itself.

On the 60L I ended up doing about 330km. Put a quick $20 in before going out yesterday, which was 13L even, and covered 150km with 13-15L. All thats been changed is the air filter and I broke the radio antenna off by accident, and now its returning ~10L/100km :nuts:

I know those differences would be affected by where the car was driven, the 60L was a 80/20 (town/highway) split, where as the 13-15L was a 20/80 split, but still you would think the difference would be quite that dramatic....

Got a job interview lined up on saturday, so with any luck I'll have her in for a service in the next couple of weeks :pray:

glad to hear mate, the biggest thing that mad my fuel consumption go down was my k & N panel filter + barrys fuel rail kit and gaskets.

thick oil hurts economy also i noticed.. my old th approching 200 000 thought i'd swap to 20w50.. economy went downhill.. 2 weeks went past.. still wasn't getting better..

ditched it and went back to 15w40 semi-synth (didn't want to try 10w but prolly would be fine!).. now it's over 200 km's and my old man inherited it off me.. still i service it with 15w oil.. and she loves it.. no noises.. clean under the rocker covers and everything.. but thats what servicing every 5K will do to an engine.. rather than the 15k intervals they leave it to.. *shudders*...

A wheel alignment gained nearly 0.5L on my AWD!! Front toe in prob.

Stay the hell away from antyres. I currently have 2 on the back, they do not hold air, eg fronts are at 30psi instead of 38 after a while, one rear was at 13, the other on 17. Not to mention they have 0 grip. I can spin a wheel with 25% throttle when its wet at 50kph+.

i know the tread started seperating from the tyres at 75% tread so i got the tyre shop to turf em check em to make sure they arn't splitting if they have a tiny crack all around the tyre ditch em before they blow up!

i went back to pirelli

Just a couple of points:

1. As has been said, you can't assume that the fuel guage is accurate. The only way to get a reasonably accurate estimate of fuel consumption (apart from a trip computer if you have one) is to compare k's covered since last filled up against the amount of fuel needed to fill up again. My money's on this being the cause of your apparent huge variations in fuel consumption.

2. Running tyres at higher pressures than recommended may give you better mileage but it will give you less grip and higher wear in the center of the tread as you're basically rounding the profile of the tyre (less rubber on the road = less rolling resistance). This risks accidents due to poor grip (unless you drive like a granny), and you may find out that the accelerated tyre wear costs you more than the extra fuel you burn with the recommended pressures. They're provided for a reason.

3. Changing engine oil and filter is dead easy; takes about half an our including cleaning up the oil catch tray. Don't leave it to a mechanic to charge you loads of cash. Use decent oil and filter and change them at least every 7.5k.

4. Changing the auto fluid is a bit more involved but I did mine (on a KJ Verada) for the first time last weekend in an hour and a half. Just be aware that to do a full flush (which you'll need) you'll use quite a lot of fluid. I had to flush mine through 3 times before it ran clear & it took 15 litres in total (about $100 from a Mitsu dealer). You might also need a filter on your model.

Sure it wasn't just your trip computer resetting? Economy always jumps up a bit for the 1st little while after that... Then it settles again.

I had my tranny ecu reset at mitso. (TJ VR-X 5 speed tippy)

Fuel consumption went from 11.5-12.5 L/100k to 9.8-10.9 L/100k

Don't have a K&N yet either...
I drive like a granny too..

I've got as low as 9.0L/100k 30% town 70% highway.

Me working shift work helps.
Morning shift has the most traffic hence more stop start so it's
around the mid 11's to mid 12's.

afternoon shift is better at high 9's to low 10's.

not booting it everywhere makes a big difference too.


Steve

Being a Verada it's going to be thirstier than a Magna for the extra weight. Before LPG I was getting around 400kms out of a tank around town and 800kms on a trip.

The main thing with fuel is your right foot.

if you have the money to, at least drop the oil and change the filter yourself.

i did mine (well i stood around and watched my dad do it for me hehe) the other week, and almost instantly i got better fuel econ - instead of my 'normal' 12.4/100km around town, im getting 10.8L/100km avg's
my car also is reving at lower RPM than before as well, by about 200rpm or more when driving at highway speeds (of the legal nature)

For 50bucks its pretty easy to change the oil and filter yourself..
(i cant say what oil i put in, just Shell in a yellow bottle!!! haha)

(saying that tho, i do know what its like to have no income and have an expensive car to run around in..)

Dirty / shot spark plugs will effect startup too - along with fuel econ and general driving...
without good clean spark, there is (not as) clean fuel burn, which often results in more fuel being injected to be burnt coz the computer thinks its running lean...

I am guessing that synthetic oils are better for fuel economy.
I took my car for service to a mechanic near my work and I saw that he used normal 20/40 oil. I didn't think about it at the time but since then the economy got worse.
I should remember to bring my own oil with me next time I go an see him...

The main thing with fuel is your right foot.
What if I told you one tank was without going over 2800RPM in 1st and 2300RPM in any other gear and it returned 16.5L/100km.

Mohit kindly hooked up his Diag system thingo to it last thursday and took a few readings. Looking mainly at the o2 sensor it appears to be within its normal operational figures, but it doesn't appear to be working correctly in my mind anyway.

For those who don't know, basically with o2 sensors they give a x.x reading, 0.0 to 0.9 is considering normal, 0.0 being lean and 0.9 being rich. If they're outside these figures then something is wrong, and it should never drop below 0.7 under high load.

Now, its always inbetween 0.0 and 0.9, but when its sitting idling it tends to spike, so like; 0.2 > 0.3 > 0.8 > 0.1 > 0.6 > 0.2 > 0.4 > 0.9 > 0.3, that kinda thing, and mohit also noticed watching the graph on the laptop when we took it round the block that the levels appeared to be dropping when I accelerated (my understanding of that is less fuel is being put into the fuel/air mix).

Is that an indication of an installation problem somewhere, a faulty o2 sensor or is that supposedly normal?

I'm still working on the job thing (bloody hard to find a part time job around my area so it seems) but I'm gonna see how I go borrow a tad off the sister to get the service done in the meantime, its started jolting really hard into 3rd on occasion now, not particularly keen on driving it into the ground any further.

How far did you drive it around the block?

I know SFA about the O2 sensor... but I had mine replaced back in January (TJ with 104k kms). The mechanic said it was on the way out, but hadn't completely carked it. He took it for a spin with something connected to the sensor. The O2 sensor was fine when the engine heated up, but when the engine was cold / on the first few kms of a drive, it wasn't working properly.

He replaced it... unfortunately fuel economy is basically unchanged, which sucks, because mine is pretty bad (9.3l/100km is my all time best) :(

Was only like 2 mins around the block, but the car had been on a 20 min drive only a couple of hours or so before, and it had been idling for 15 mins before we took off. So yeah it was warm.

i can't get over mine..

babing it to work.. just in normal auto mode.. returns on average 13.5.. no air con.. no windows down (maybe just a crack) speeds vary from stop to 80km/h...

as soon as i get up it even once.. thats it.. low 14's and she won't dip below that..

i have never ever had it in single digits, nor had it constantly around the 10-11 (which is were they are ment to hang)

i've tried all sorts of resetting like computer and g/box.. and then baby drive it to 'learn' that shift pattern.. still next to no difference.. which to me means somthing mechanicle/sensor related..

i'm getting a bit jack of it.. i drive about 550 km a f/t and usually have to fill up once and a top up in the second week..

i have been a bit lazy of late, and the economy was getting up there, to the point of returning about 14.8l/100ks..
last week, had a bit of time up my sleave and decide to give the TJ some attention..
cleaned the airfilter.. (standard paper one)
got a bottle of nulon engine flush, did a full idle run for 15min with the flush in
drained it all out...
put 4L of cheap clean valvoline oil in (cost me $13), and idled for another 10 minutes
fully drained, removed and replaced the oil filter
and put the new oil in (castrol GTX3)
change the front spark plugs....

now i'm getting 11.2l/100ks, the engine runs quieter, and idles smoother and drives overall better...cost me all up about $80 for all the materials

next week, i might change the fuel filter and also put some injecter cleaner in, hopefully it will dip back down into the 10's. which is ideally where i want it to be

The biggest reduction in fuel consumption with mine has been going easy on the pedal.

Ive dropped from 9.5-9.8 down to 8.8-8.9 without changing anything (parts).

I only give it enough juice to get it up to speed and keep it there, nothing more then it needs, and back off well before lights.

This isn't something you can do for 10 mins and say "i didn't notice anything" it is a conscious effort that needs your complete attention while driving. And only once you do this, will you will get results.

All my results are performed with regular unleaded.

i can't get over mine..

babing it to work.. just in normal auto mode.. returns on average 13.5.. no air con.. no windows down (maybe just a crack) speeds vary from stop to 80km/h...

as soon as i get up it even once.. thats it.. low 14's and she won't dip below that..

i have never ever had it in single digits, nor had it constantly around the 10-11 (which is were they are ment to hang)

i've tried all sorts of resetting like computer and g/box.. and then baby drive it to 'learn' that shift pattern.. still next to no difference.. which to me means somthing mechanicle/sensor related..

i'm getting a bit jack of it.. i drive about 550 km a f/t and usually have to fill up once and a top up in the second week..

Ditto mate, I can't seem to get below 13.5L/100 with just careful driving. Can't figure out why.

And the Verada vs. Magna weight isn't so much to make a huge different in economy.

I should be quiet about getting 7.3l/100 in a 300km trip.hmm.I guess it was because I was doing 85kph the whole way due to stupid learner speed limits.maybe going a few kph under the speed limit in a 100kph zone might help a bit

I should be quiet about getting 7.3l/100 in a 300km trip.hmm.I guess it was because I was doing 85kph the whole way due to stupid learner speed limits.maybe going a few kph under the speed limit in a 100kph zone might help a bit

I've read that when they do the Hwy / city cycle when test new cars the hwy cycle is done at 80km/h......... constant speed on a flat road..... 7.3 is pretty good for a magna.....

Steve

i can't get over mine..

babing it to work.. just in normal auto mode.. returns on average 13.5.. no air con.. no windows down (maybe just a crack) speeds vary from stop to 80km/h...

as soon as i get up it even once.. thats it.. low 14's and she won't dip below that..

i have never ever had it in single digits, nor had it constantly around the 10-11 (which is were they are ment to hang)

i've tried all sorts of resetting like computer and g/box.. and then baby drive it to 'learn' that shift pattern.. still next to no difference.. which to me means somthing mechanicle/sensor related..

i'm getting a bit jack of it.. i drive about 550 km a f/t and usually have to fill up once and a top up in the second week..

Try this (if you haven't already)
One weekend go for a long drive and use the cruise control as much as you can... jump on a long freeway or something and see if you start to dip to really low figures...

If you don't then there is something going on there...

steve

last week i went down to somersby. I topped it up at the twin servos at wyong, reset the trip meter and off i went. 8.9l/100km, and ave speed of 112.8km/h, which equals about 2800rpm, in a 2000 tj sports manual with a k&n filter only. Windows closed, and a/c on. Drove to work and back, and dropped my girl at work a couple of times and the ave went up to 10.5l/100km.

My girl drove to work and back yesterday, 40km round trip, and her average went from 10.0 to 10.6.....not happy jan.

Try this (if you haven't already)
One weekend go for a long drive and use the cruise control as much as you can... jump on a long freeway or something and see if you start to dip to really low figures...

If you don't then there is something going on there...

steve

I've tried this. Did about 130kms starting with a full tank, 100kms highway 30kms town (Sydney and Parramatta Rd, urgh) and filled up again when I got home. Got 8.9L/100. It just the around town pottering that's killing my economy. Even so, I don't think I should be seeing over 13L/100.

I've tried this. Did about 130kms starting with a full tank, 100kms highway 30kms town (Sydney and Parramatta Rd, urgh) and filled up again when I got home. Got 8.9L/100. It just the around town pottering that's killing my economy. Even so, I don't think I should be seeing over 13L/100.

Depends what the traffic is like....

I sit in Parramatta road traffic from about 2:45pm to anything up to 3:30pm some days when it's bad and have seen a freshly filled tank (Within two days of filling) go from mid 9's to 11.5-12L/100 in just one sitting...Pisses me off....

Hell today it went from 9.8 to 11.9 L/100... I filled up tues night....
after a few days of driving (after say 150-200k's) it becomes less sensitive to traffic.

I've actually started a new "game" to stop me speeding like a lunatic.... i try and better my fuel economy from the previous week... It's working too.....prolly saving like a whole 5 bucks per tank....
Though when I filled the tank once and reset the trip computer etc... I've seen "distance to empty" at 750kms.... hmmmmmm it didn't!!!! lol more like 630km's

But damn it.... sometimes it just feels good to give it the boot off the lights and when overtaking.....

Steve

2005 TW 3.0L

i removed all the front mud guard flapping, and catback exhaust, im doing 12.6L/100km on average not with heavy foot all time, get about 450km on full tank per week.

I've actually started a new "game" to stop me speeding like a lunatic.... i try and better my fuel economy from the previous week... It's working too.....prolly saving like a whole 5 bucks per tank....

Tried that for a few weeks, even found some music that made me lighten the foot, but it didn't take long to get old :P

Tried that for a few weeks, even found some music that made me lighten the foot, but it didn't take long to get old :P
Unfortunately thats the P plater disease, random bursts of uncontrollable adrenaline which makes you want to boot it a bit. Comes to me every so often, not too much lately knowing how much the fuel is hurting my pocket. I've used about 1/3 of a tank this tank, done around 100km I think :( Going in for a service next Friday, hopefully that helps my fuel issues.

I suppose there are much worse things I could spend my money on then petrol ;)

I should be quiet about getting 7.3l/100 in a 300km trip.hmm.I guess it was because I was doing 85kph the whole way due to stupid learner speed limits.maybe going a few kph under the speed limit in a 100kph zone might help a bit
I've done 7.6L/100km before one day which involved roughly 80% freeway driving, booted it a few times too :confused: The car is weird...

Going in for a service next Friday anyway, we'll see how it goes after its all serviced.

im not sure if this has been suggested yet, as i only skim read back 2 pages worth.

when sitting at the lights, waiting for them to go green, have the trans in neautral, and dont engage drive until the lights are green.

my tc average is at 10.3/10.6 l /100km (50/50 highway - city), and i put it in neautral all the time at the lights - alo helps suppress the racing instinct too i found. hehe
i wonder why my car is suddenly being nice to me by not drinking so much fuel...

I rarely leave it in drive at the lights. I'm a manual driver at heart lol hate the "driving itself" thing automatics do when you take your foot off the brake. I usually shift into neutral too when I'm parking or whatever, roll to stop, dunno if thats good for the auto or not though :P

the 3rd gen i feel is pretty good for that.. it's not like most auto's where they tend to pick up speed down hill.. they have a degree of engine/tranny braking if you like to call it that..

My fuel economy improved out of sight when I put work/ corporate number plates on the car, makes me think twice about sinking the lead foot into it.
I like having my vehicle in gear at all times including when stationary, auto or manual. maybe I'm a control freak, but if its in neutral I have no real control over the vehicle

I like having my vehicle in gear at all times including when stationary, auto or manual. maybe I'm a control freak, but if its in neutral I have no real control over the vehicle
Well in a manual I'm in gear too normally when I'm stopped at the lights, but the clutch is in so if you lift off the brake your not going to drive off without doing anything. I see your point though, if its out of gear you can't move as quickly if you need to.

Well I think the trick is to accelerate and brake gently, shift into N when at a standstill instead of leaving it in D to take the load off the engine, switch off the AC where ever possible and if you have it on, keep the windows up so that you don't create unneccessary drag, sit in the slip stream of semi trailers on the freeway and make sure your tyres are inflated to the correct PSI. My car probably weighs over 1600kg with me in it plus Dynamat, carpet underlay everywhere, 235 section tyres and my trip compueter consistently displays an average fuel consumption in the 10L per 100km range with 40% freeway 60% city driving. Occasionally I will have a blast but generally drive pretty sedately.

However, I estimate that I drive a minimum 628km from Tuesday to Tuesday and can manage that on one $80 fill. That $80 at a assumed price of say $1.50 per litre, gives me 53.34 litres of overpriced ULP. From that, my average fuel consumption is only 8.49L per 100km which is much less than the trip computer reading. So perhaps the trip computers read a little optimistically?

i find it interesting people saying to go to a k&n air filter. i would like to ask why they say this.

they way i see it is that a k&n air filter will flow better and give you more power, however with it flowing better at any given throttle position it will let more air through, thus giving the AFM a higher reading and the ecu will add more fuel to compensate. so if you are sitting in traffic and just blip the throttle go get moving a bit more you will use a fraction more fuel as there was more air let in.

however if you are cruising at a set speed there will be no difference as you require the same amount of air and fuel to make the power to go at the speed. so with the k&n filter you will have a lower throttle percentage, however the AFM will still be reading the same volume of air, so you will be using the same amount of fuel. then there is also the fact that the O2 sensor controls the AFR during low load.

when you accelerate you will accelerate faster (so be accelerating for a shorter period of time) due to being more free flowing, however once again you will be using more fuel for any given throttle percentage while accelerating. so basically no matter what you do as far as intake mods go, you can't gain fuel economy. the reason being that any intake mod allows more air to flow into the motor, however that air is metered so any rise in the amount of intake air will give a rise in the amount of fuel added.

exhaust mods will give some fuel economy, but if you go too far you can lose it. however the best way to gain fuel economy if to get a piggy back computer to control your fuel. this way if your car is running a bit rich you can lean it out, gaining both power and fuel economy.

also getting your injectors cleaned professionally can help too, as a dirty injector may not spray the fuel evenly so it doesn't combust in the ideal way, which means you aren't getting as big of a bang as possible, so you are using more fuel to get the same power.

another tip is to make sure that your thermostat is working properly. if it isn't shutting properly you car will take longer to warm up, so it will be running on cold start enrichment for longer and waisting fuel.

Have to agree on the k&n, I always put one on any vehicle I have, but this car is the only one to not really show improvement.
My fuel consumption usually seems closest to doddskis, best of 9.7/100 on the highway, and high 11's - 12.7 round town, 38psi in the tyres.
We've all commented on these cars staying in 5th gear at low speeds, but there is probably better figures acheivable with some grandma driving.


EZboy, did that alignment sort your tyres wearing unevenly?

this week i used fuel from a different servo (i didnt pay for it - a mate and his lovely company fuel card did!), i got it from a Shell - just the standard 91ron

admittedly i have been doing a LOT of highway and cruise control driving and its mostly all been on cold nights as well.

T/C has been reading out a neat 10.0L/100km average since i got the car filled up earlier in the week.

also another tip for making sure that your getting the best possible fuel econ outa your car at all times;
keep it CLEAN - inside and out.

(the way i think about it anyhow-) is if the outside of the car has a lot of dirt and whatever sticking to it, its going to be adding to the drag effect of the air the car is trying to pass through, only minutely yes thats a given
but - also think about the weight factor as well, more weight = more fuel needed to move the car.

keep the interior of your car clean / vacummed out as well, it all adds to the weight factor too.

in one of my old cars, i ended up being a bit of a rubbish car coz i never threw anything out.. took the rubbish out and i instantly got better fuel econ.

so in all - car looks great (as in clean inside and out) and it will also help save you a fraction (dont expect huge savings/changes out of it tho!) in fuel costs.

this week i used fuel from a different servo (i didnt pay for it - a mate and his lovely company fuel card did!), i got it from a Shell - just the standard 91ron

admittedly i have been doing a LOT of highway and cruise control driving and its mostly all been on cold nights as well.

T/C has been reading out a neat 10.0L/100km average since i got the car filled up earlier in the week.

also another tip for making sure that your getting the best possible fuel econ outa your car at all times;
keep it CLEAN - inside and out.

(the way i think about it anyhow-) is if the outside of the car has a lot of dirt and whatever sticking to it, its going to be adding to the drag effect of the air the car is trying to pass through, only minutely yes thats a given
but - also think about the weight factor as well, more weight = more fuel needed to move the car.

keep the interior of your car clean / vacummed out as well, it all adds to the weight factor too.

in one of my old cars, i ended up being a bit of a rubbish car coz i never threw anything out.. took the rubbish out and i instantly got better fuel econ.

so in all - car looks great (as in clean inside and out) and it will also help save you a fraction (dont expect huge savings/changes out of it tho!) in fuel costs.

you must of had alot of rubbish in the car to make a difference with your fuel economy! if weight is a problem take the subs or unnecassary equipment out of your car then!!!

just my opinion

mike

you must of had alot of rubbish in the car to make a difference with your fuel economy! if weight is a problem take the subs or unnecassary equipment out of your car then!!!

just my opinion

mike

my car is completely stock :P
the only difference in audio, is i have replaced the rear speakers with Clarions - NO Amp,
the headunit is Alpine.

thats the only non standard part of my car :P
unless you count dash mats and floor mats? lol :)

Got the car back from service today, mechanic claimed the air filter was completely blocked, so it was replaced as part of the service, will be fine from now on I was told. Driven 50km tonight, indicated 1/4 of a tank used....my **** its running better now!

Annoying but ah well...maybe I've got a dud with fuel economy lol Or maybe the o2 sensor is buggered despite giving the correct range of readings :nuts:


:confused:

Got the car back from service today, mechanic claimed the air filter was completely blocked, so it was replaced as part of the service, will be fine from now on I was told. Driven 50km tonight, indicated 1/4 of a tank used....my **** its running better now!

Annoying but ah well...maybe I've got a dud with fuel economy lol Or maybe the o2 sensor is buggered despite giving the correct range of readings :nuts:


:confused:

and whilst you are there changing the o2 sensor, save some money and get a k&n, the life on that thing will save you money after about 3-4 paper filter changes. the cost of each paper filter is about $20odd-$30 (something stupid) a k&n off ebay is $75 exclude postage, go figure which will more cost effective.

i got approx 150km per 1/4 tank in the TF and about 120-130km in the TL.

Last time i heard your car it sounded like it had an exhaust leak or a hole in the muffler

Might wanna check that out too ;)

and whilst you are there changing the o2 sensor, save some money and get a k&n, the life on that thing will save you money after about 3-4 paper filter changes. the cost of each paper filter is about $20odd-$30 (something stupid) a k&n off ebay is $75 exclude postage, go figure which will more cost effective.

i got approx 150km per 1/4 tank in the TF and about 120-130km in the TL.
Then add the cost of the K&N recharge kit... Not exactly better value but it's kinda cool saying you have a K&N though, right...? right?

Why don't you try adding a hiclone? :bowrofl:

K&N recharge kit was $19.99 from Autobarn.

and whilst you are there changing the o2 sensor, save some money and get a k&n, the life on that thing will save you money after about 3-4 paper filter changes. the cost of each paper filter is about $20odd-$30 (something stupid) a k&n off ebay is $75 exclude postage, go figure which will more cost effective.

i got approx 150km per 1/4 tank in the TF and about 120-130km in the TL.
I will do the K&N, but at the moment I'm only doing what NEEDS to be done to get the economy back and get it running smoothly. Probably going to have to do the o2, might take Type40 up on his offer a while back there :P I'll have to find out if he checked the fuel filters too, didn't think to mention it.


Last time i heard your car it sounded like it had an exhaust leak or a hole in the muffler

Might wanna check that out too ;)
Crack in the centre muffler. I'm not too fussed about that, I don't think its going to be causing any issues apart from noise, I'll worry about that when I change the whole exhaust system over I think.

Car will also need the rear discs replaced to fix my handbrake issue, and all the drive belts replaced fairly soon.

Edit: Just checked the fuel guage, this morning its 1/8 higher than it was when I parked last night :nuts:

ZOMG you have a car that regenerates its fuel supply overnight!

ZOMG you have a car that regenerates its fuel supply overnight!
lol Its done that a bit, but not often by that much!

Just went up to the supermarket, left the car in the car park for 5 mins, come back out, cranking, cranking, cranking...nothing....:redface: Had to let it sit for a minute, started on its 3rd go :doubt:

Spoke to my mechanic about it on the phone just then, he's not sure what that is, but told me to monitor it and if it does it again to let him know. Really odd because nothing sounded out of the ordinary and the cranking was normal :confused:

ZOMG you have a car that regenerates its fuel supply overnight!

if all cars were like that, i wouldn't be drulling over a LS3 HSV this morning, with the cost of petrol at the back of my mind

Alrighty, gonna threadmine my own thread because I have more questions! :thumbsup:


Had the car on an Exhaust gas analyzer today to find out whats playing up, and to my surprise every single reading was absolutely spot on. So, if thats anything to go by, all the sensors are reading perfectly, theres no leaks, its not running too rich nor too lean.

Add that to grandma style driving which I've adopted for 95+% of my driving, and a mixture of town/highway in the 70/30 region, and surely I shouldn't be still getting 16.5L/100km as an average per tank.

Speaking to the mechanic about it he seems to think that's about right, that I should only be seeing 350-400km on 60L with the type of driving I'm doing, I beg to differ though, I don't see anyone on here complaining of figures like that, and you can't all drive everywhere on the highway!

My mech's only other suggestion was things like compression, which would also lead to decrease in engine performance, unlikely given it happily goes as hard as many other 3.5's with the same sort of the stockiness to them.

I'm stumped....

If it wasme i would of replaced the o2 ages ago, its a piewalk to change should get change out of 120 if you get a mechanic to do it, and you have probably spent more time/money then that amount trying to figure out what exactly is the problem, even with my blower i still get 600k's to a tank driving easily, but 300 if i wanna listen to the blower :D also have you reset the ECU? might not fix it but its a suggestion if you are stumped.

Yeah that's bad, I never saw figures like that in my KH even when driving "enthusiastically". Most of my driving was around town, and after an oil change/filter my economy increased from 14.5L/100 to 13.6L/100.

16.5L/100 when babying is just, wow.


also have you reset the ECU? might not fix it but its a suggestion if you are stumped.

noticed a bit of a difference doing this as well. Also sorted out the slight vibration when stationary in D.

16L/100km is a bit rich indeed

altho, but your own admission, you are doing mostly town style driving - what sorta town driving? is it stop start every block for traffic lights, are you spending a lot of time in your car just idling as well?

aircon in city stop start traffic lights and heavy traffic situs does nothing for fuel econ - however, my car spends (only) half the day in traffic of my commute to and from work (works out at about an hour maybe at the most for stop starting) - and i got last week 11.8L/100km!!!

i would suggest taking the car out for a looooong highway drive if you can
like 200kms of pure highway driving - its possible the the bores have glazed over, and glazed bores amoung over things arnt good for fuel econ im told.

Yeah I don't care what the mechanic says, o2 sensor is something I need to change, something has to be playing up. And now, thanks to MitchellO here, the o2 sensor change will become a reality for quite a lot less than what one would usually cost :cool: Cheers man.


altho, but your own admission, you are doing mostly town style driving - what sorta town driving? is it stop start every block for traffic lights, are you spending a lot of time in your car just idling as well?
Of the ~70% town driving, about 80% of that is fairly free flowing traffic just slowing for round-a-bouts, traffic lights etc, the other 20% is heavy traffic involving a bit of bumper to bumper.

The ~30% of highway driving 95% of the time is cruise set to an indicated 102km/h-ish.



i would suggest taking the car out for a looooong highway drive if you can
like 200kms of pure highway driving - its possible the the bores have glazed over, and glazed bores amoung over things arnt good for fuel econ im told.
I've done that before, worked out to about 7.6L/100km avg. Fuel economy wasn't any better around town after that.

I'm pretty sure the car has always drunk fuel like this since I bought it, just never noticed before because I used to do about 40/60 town/highway when I first got the car, since then I've stopped needing to go to most places that I took the freeway for. It used to be around mid 13's to low 14's when I drove with that split.

With economic driving, the rpm chews the juice faster than throttle position.

What Hypermilers have discovered is a brisker acceleration to get to cruise speed/gear earlier pays off. Using up to half throttle, change gear up by 2500rpm.

In suburban driving, this may mean gear up-skips also eg accelerating in 2nd then cruising in 4th, or accelerating in 3rd, then cruise in 5th.

Now lets talk of a skill called Acceleration Sense. This is something the P-plater accelerating up to the red light does not have, but the guy that slowed earlier to pass the P-plater on green with the rolling start does have. The earlier you wash of speed for the red ahead, the higer your start speed and gear can be.

For ascents, go for the tallest gear without having to fully floor the pedal.

For long descents, go for the tallest gear that can hold the car's speed with occasional braking.

Let us know how this goes.:cool:

All common sense really.

I can say as a P plater I drove like that in my Verada, and got about 13.7L/100 with most city driving.

With the manual I often skip 2nd all together, or start in 2nd and skip 3rd, the extra gears just aren't necessary in "normal" driving :P

Good post Ogre, and to be honest that's essentially how I drive the car atm. I've tried babying it to the point where it shifts in each gear around 2000rpm, and it worked out worse than my normal driving pattern. I figure the less time I spend building up speed (without being extravagant) and the less I stop (like your traffic like scenario) the better.

Suppose I'll see what happens when the o2 sensor is changed.

With economic driving, the rpm chews the juice faster than throttle position.

What Hypermilers have discovered is a brisker acceleration to get to cruise speed/gear earlier pays off. Using up to half throttle, change gear up by 2500rpm.

In suburban driving, this may mean gear up-skips also eg accelerating in 2nd then cruising in 4th, or accelerating in 3rd, then cruise in 5th.

Now lets talk of a skill called Acceleration Sense. This is something the P-plater accelerating up to the red light does not have, but the guy that slowed earlier to pass the P-plater on green with the rolling start does have. The earlier you wash of speed for the red ahead, the higer your start speed and gear can be.

For ascents, go for the tallest gear without having to fully floor the pedal.

For long descents, go for the tallest gear that can hold the car's speed with occasional braking.

Let us know how this goes.:cool:


not sure i agree with all that. If i stick it in second on a fairly large descent, and just let it roll away, the revs climb to maybe 3500-4000rpm but indicates fuel usage as barely 2l/100km.

Back to the poster above though, 16l/100km with grandad driving is just rediculous. HAS to be a problem somewhere. I see maximum of 15 with stop-start enthusiastic driving on cold mornings all week long. Taking it easy, as low as 9 is very achievable.

Here's what you should be getting.....

Green Credentials
Fuel Urban (l/100km) 11.0
Fuel Extra Urban (l/100km) 7.2
Fuel Combined (l/100km) 8.6

Things I did to keep good economy on my TH 2000 3.5 (still experimenting with the new TR)

Changed the rear exhaust to a Lukey High Flow

Changed air filter OEM

Used BP Ultimate on every fill 98 ron but contains cleaners and detergents ....noticed considerable difference to low end torque and performance. Increased fuel economy by approx 8% (Costs more but you get the money back in economy and more grunt easily)

Tyres were filled with Nitrogen when I got a new set (Now I don't have to stuff around with trying to work out whether they are inflated at the correct pressure)

Serviced regularly and oil changed every 5000kms

I was getting 10.9 and could still give it a whack every now and then.
On the highway down to 8.5's or there about (lowest was about an 8.1 Coffs to Gold Coast)

My car (both KH and TL) show 0.1L/100 when the revs are above idle coasting.

not sure i agree with all that. If i stick it in second on a fairly large descent, and just let it roll away, the revs climb to maybe 3500-4000rpm but indicates fuel usage as barely 2l/100km.
I think what he means is don't select a gear that has you accelerating to hold the speed limit on a downhill. ie. Don't put it in 2nd and accelerate down the hill if 3rd will hold you at the speed limit with the odd touch of the brakes.

I don't see engine braking as something that really affects fuel economy, and I use it as appose to riding my brakes all the way down a long hill, unnecessary wear and tear on the pads.

I've thought about this over and over, and I can't see how anything else could be effecting the economy so badly. I've fixed the leaks, I've had it all serviced, I know the drive belts need replacing but they're not going to affect economy, and I've adjusted my right foot accordingly (did that a LONG time ago). I've even gone as far as checking tyre pressures and all the seals in the engine bay.

The sensors might be giving all accurate reads on idle, and when the throttles open, but I can't help but think its a different story when the car's in gear moving, obviously you can't have a stand alone exhaust gas analyzer hooked up to it when moving so its challenging to check without a dyno. I'll hook up the new o2 sensor when it gets here hopefully early next week, and see how it goes from there on in.

Edit:

As far as the above fuel figures go that Johnnyred has posted, I'm not expecting an average of 11L/100km, I'd be happy with anything in the 12's realistically. I understand that if I only do bumper to bumper traffic locally one week its going to be crappy, but not from the mix of driving I do, I spend little time in peak hour traffic.

I think I'll be trying PULP as well when I can afford to :) I did once before but I only gave it one or two tanks.

dont bother with PULP, you will get no tangible benefits because the engine can't advance or retard timing to suit the fuel octane. If anything, throw the cheaper E10 in the tank. its rated to 94RON, and will do exactly the same job as PULP/standard but 3c cheaper per litre.

dont bother with PULP, you will get no tangible benefits because the engine can't advance or retard timing to suit the fuel octane. If anything, throw the cheaper E10 in the tank. its rated to 94RON, and will do exactly the same job as PULP/standard but 3c cheaper per litre.
Thats arguable, a few people I know run PULP in 3rd gens and they benefit from better fuel economy. I only haven't bothered with mine to this point because I can't afford it.

dont bother with PULP, you will get no tangible benefits because the engine can't advance or retard timing to suit the fuel octane. If anything, throw the cheaper E10 in the tank. its rated to 94RON, and will do exactly the same job as PULP/standard but 3c cheaper per litre.
Yeah wont advance or retard the timing to make more POWER..
Will see benefits of FUEL ECONOMY though, My Nannu only uses PULP as he gets another 80kays from the tank.

']My Nannu only uses PULP as he gets another 80kays from the tank.
And thats by XD standards right ? :D

I'll back the BP Ultimate anytime the difference it made was tops....at times I was paying around $120 when petrol hit the high mark. But I just gritted my teeth and paid up I knew my engine power and economy was better for it.

Using low grade green is a false economy it doesn't burn as efficiently thus simple equation low burn more petrol to make engine go.

You can go here to find out...

http://www.bp.com/subsection.do?categoryId=9015023&contentId=7027962

And thats by XD standards right ? :D
TF standards dude....

']TF standards dude....
Now I'm confused, didn't know anyone in your family had a TF..:confused:

Now I'm confused, didn't know anyone in your family had a TF..:confused:
I have 2 nannus dude not 1, so its my other nannu. jesus dont you keep tabs on all my family members? :P

I'll back the BP Ultimate anytime the difference it made was tops....at times I was paying around $120 when petrol hit the high mark. But I just gritted my teeth and paid up I knew my engine power and economy was better for it.

Using low grade green is a false economy it doesn't burn as efficiently thus simple equation low burn more petrol to make engine go.

You can go here to find out...

http://www.bp.com/subsection.do?categoryId=9015023&contentId=7027962

pffft carried out on a Camry which utilises the extra Octane by means of a knock sensor, Which a 3rd Gen Magna/Verada doesnt have.

']I have 2 nannus dude not 1, so its my other nannu. jesus dont you keep tabs on all my family members? :P
lol I should try harder. Its a wagon isn't it? Its coming back to me I think.

pffft carried out on a Camry which utilises the extra Octane by means of a knock sensor, Which a 3rd Gen Magna/Verada doesnt have.

hmmm....that was a good counter argument. :doubt:


Power demonstrations
See BP Ultimate Unleaded deliver power benefits in the following demonstrations.

An independent testing facility in the UK was asked to test BP Ultimate Unleaded against ordinary fuel to see if there really is a difference. A Mitsubishi Evolution high performance car repeated several power tests on a dynamometer - rolling road - which allowed the power output of the car to be graphically and accurately measured.

The same vehicle produced 6% more power at 7000rpm when running on BP Ultimate Unleaded versus ordinary fuel …

BP now owes me a tank of fuel for promoting their product....

hmmm....that was a good counter argument. :doubt:


Power demonstrations
See BP Ultimate Unleaded deliver power benefits in the following demonstrations.

An independent testing facility in the UK was asked to test BP Ultimate Unleaded against ordinary fuel to see if there really is a difference. A Mitsubishi Evolution high performance car repeated several power tests on a dynamometer - rolling road - which allowed the power output of the car to be graphically and accurately measured.

The same vehicle produced 6% more power at 7000rpm when running on BP Ultimate Unleaded versus ordinary fuel …

BP now owes me a tank of fuel for promoting their product....

BECAUSE IT USES A KNOCK SENSOR TO ADJUST DETONATION CAUSING A CLEANER BURN! Doesnt happen on a standard magna :bowrofl:

Short drives kills your economy as well. Perhaps you live too close to tafe.
Cold engine as well...kills economy.

Short drives kills your economy as well. Perhaps you live too close to tafe.
I've considered that, though the fuel consumption didn't differ at all on weeks I didn't drive to tafe, so I've somewhat ruled that out as a cause for a huge increase. Its always warm before it leaves home of a morning for tafe any who, so it shouldn't be too bad.

I've considered that, though the fuel consumption didn't differ at all on weeks I didn't drive to tafe, so I've somewhat ruled that out as a cause for a huge increase. Its always warm before it leaves home of a morning for tafe any who, so it shouldn't be too bad.

so you are saying that you leave the car on idle to warm it up before driving, theres your fuel economy issue then. If you read your ownnr's manual, mitsu does not recommend you to warm up the car in that fashion, but instead drive it gentlely until it reaches operation temp, the car also warms up faster this way. Leaving the car on idle to long can cause a build up of carbon deposits within the engine.

so you are saying that you leave the car on idle to warm it up before driving, theres your fuel economy issue then. If you read your ownnr's manual, mitsu does not recommend you to warm up the car in that fashion, but instead drive it gentlely until it reaches operation temp, the car also warms up faster this way. Leaving the car on idle to long can cause a build up of carbon deposits within the engine.
First I've ever heard of letting a car reach its optimum temperature before driving off being bad for the car...

I do that mainly for my own comfort, because the cabin is warm when I go to leave then, I only ever do that before tafe, no other time and letting it idle for 5 mins before i leave of a morning hasn't affected the overall economy of the car in the slightest since I started doing it. If that was effecting the economy by 4L/100km I would have noticed by now I'm sure lol

First I've ever heard of letting a car reach its optimum temperature before driving off being bad for the car...

I do that mainly for my own comfort, because the cabin is warm when I go to leave then, I only ever do that before tafe, no other time and letting it idle for 5 mins before i leave of a morning hasn't affect the overall economy of the car in the slightest since I start doing it. If that was effecting the economy by 4L/100km I would have noticed by now I'm sure lol

if you have an answer to all the suggestions then you shouldn't have an issue with your economy. I'm getting 12's at the worst and i'm not trying to get it down either, i just can't get it any higher in the traffic environment during my daily drive.

if you have an answer to all the suggestions then you shouldn't have an issue with your economy.
I'm simply giving answers for the suggestions I have answers to. Never gonna narrow it down otherwise :P I'm just saying I know the morning idling hasn't been effecting it, not greatly anyway.

+1 to it being an oxy sensor fault.

Idling your car to warm it up uses piss all fuel around about a litre per hour.

I'd be interested to see your exhaust gas figures not just for Air/Fuel ratio but also for CO, CO2 and NOX.

I think what he means is don't select a gear that has you accelerating to hold the speed limit on a downhill. ie. Don't put it in 2nd and accelerate down the hill if 3rd will hold you at the speed limit with the odd touch of the brakes.

I don't see engine braking as something that really affects fuel economy, and I use it as appose to riding my brakes all the way down a long hill, unnecessary wear and tear on the pads.

That's spot on.

Sometimes, however, depending on the slope, your vehicle's weight and the gear spacing, you may need to choose the lesser of two evils. If the higher gear would require frequent braking, but the lower gear would need to use a bit of throttle, then I would put safety above economy for the longer descent and use the lower gear to avoid the brake fade.

Troubleshooting philosophy: Once you have eliminated all likely causes (Including the O2 sensor), whatever remains, however improbable, must be the cause.

For example, if driving style, rolling resistance, and drivetrain issues have been eliminated, and you've eliminated engine maintenance issues such as lubrication, timing, fuel and air issues, then something unlikely could be the culprit eg a thermostat that opens too cold could make the ECU set a rich warm-up mixture. Have you had a cooling system specialist check the nominal temperature?

First I've ever heard of letting a car reach its optimum temperature before driving off being bad for the car...

I do that mainly for my own comfort, because the cabin is warm when I go to leave then, I only ever do that before tafe, no other time and letting it idle for 5 mins before i leave of a morning hasn't affected the overall economy of the car in the slightest since I started doing it. If that was effecting the economy by 4L/100km I would have noticed by now I'm sure lol

Its not healthy for the engine at all. Leaving a car idling from cold before being driven increases undue component wear. The engine needs the higher revs during the first few minutes to ensure good oil circulation through the ancillaries.

First I've ever heard of letting a car reach its optimum temperature before driving off being bad for the car...

I do that mainly for my own comfort, because the cabin is warm when I go to leave then, I only ever do that before tafe, no other time and letting it idle for 5 mins before i leave of a morning hasn't affected the overall economy of the car in the slightest since I started doing it. If that was effecting the economy by 4L/100km I would have noticed by now I'm sure lol
You would be surprised how much fuel it uses doing that. If you had a trip computer you can literally see it using litres at idle. My guess is that perhaps .3 to half a litre is wasted in warming up you engine in this way and if you do that everyday at lets say .5 per day there is 3.5 for the week just wasted. What i do when setting off in the morning on a cold engine is never to go over 2500 rpm until warm and use light throttle inputs. Try it and see. You can live with being cold for a minute or 2!

Yeah idling does use a fair bit, couple of litres per hour I believe :shock:

I just tested it and it used between .2 and .3 litres in 5 mins.

I just tested it and it used between .2 and .3 litres in 5 mins.


....another busy Saturday morning in Geelong, I see. :bowrofl:

First I've ever heard of letting a car reach its optimum temperature before driving off being bad for the car...

I do that mainly for my own comfort, because the cabin is warm when I go to leave then, I only ever do that before tafe, no other time and letting it idle for 5 mins before i leave of a morning hasn't affected the overall economy of the car in the slightest since I started doing it. If that was effecting the economy by 4L/100km I would have noticed by now I'm sure lol

Old cars yes, new cars no, just drive them and they are fine.
Knock sensor is to detect the higher octane fuel and adjust timing accordingly to make better use of the higher octane fuel
I think its Naive to think that because it doesn't have a knock sensor you can't get better economy when clearly many people do!

Ethanol contains less energy than petrol, so fuel consumption increases when ethanol is blended into petrol. At the 10 per cent blending level, fuel consumption increases by about 3.5 per cent, so motorists have to buy 3.5 per cent more fuel to travel the same distance.

NRMA - http://www.openroad.com.au/motoring_carcare_ethanolinpetrol.asp

Ethanol contains less energy than petrol, so fuel consumption increases when ethanol is blended into petrol. At the 10 per cent blending level, fuel consumption increases by about 3.5 per cent, so motorists have to buy 3.5 per cent more fuel to travel the same distance.

NRMA - http://www.openroad.com.au/motoring_carcare_ethanolinpetrol.asp


Making the 3c saving a waiste of time cause you spend more on fuel.. Der.. all marketing gimmiks!

Short drives kills your economy as well. Perhaps you live too close to tafe.
Cold engine as well...kills economy.

I've considered that, though the fuel consumption didn't differ at all on weeks I didn't drive to tafe, so I've somewhat ruled that out as a cause for a huge increase. Its always warm before it leaves home of a morning for tafe any who, so it shouldn't be too bad.
Yeah man, move further away so you get better economy :nuts: :bowrofl:

thought i might give you a target to aim for, this is a combination of city/suburban driving and some freeway... :)

thought i might give you a target to aim for, this is a combination of city/suburban driving and some freeway... :)
Boozer-->:nutkick:<--Lugo

:P

:owned:

Thanks Irvin.....


Lemmie know when your ready to swap gearboxes then aye.

Thanks Irvin.....


Lemmie know when your ready to swap gearboxes then aye.

so its my gearbox now?
You wanted a verada because of climate control and power windows... They come auto only if you haven't noticed.

Throttle body influences fuel consumption. With my intake off, I decided to clean my TB, was supprisng how black it actually was.

Now my fuel consumption has decreased down to around 12, which is pretty good considering its just city driving.

Just an update on my TR 1991 230,000 kms on the clock new exhaust and new filter...filled with BP Ultimate 98 RON I just got 500 / 57.8 Litres that's 11.56 city driving.
I'm happy with that better than using sugar cane petrol :D

Bit of an update. Last week it ran 14.5L/100km avg from driving slower than my grandparents, as in steadily up to the speed limit not exceeding 2500RPM in any gear through a constant acceleration, and speeds of UP TO 30km/h in side streets between all the terrible speed humps in my area to stop it from doing 2nd to 3rd to 2nd changes every 100m.

This week I ran 15.0L/100km dead completely throwing the economy idea out the window, full throttle here and there, overtaking and so on. This is the result of resetting the ECU the day I filled up last week after Type40 so ingeniously suggested to me, given it hadn't been done since replacing the muffler. Why I didn't think to do that straight away is beyond me, guess I'm a little bit stupid :D

Still waiting on my delivery of o2 sensor from MitchellO, we've agreed Aus Post can be terribly slow at times, but I'm confident it'll turn up, not unusual for things to take 2-3weeks to get to me from NSW even though my average delivery time from the US is 2-3 days..:nuts:

We shall see.