Hi am new to these forums i have a few questions

-Im not that a heavy footed driver and i drive short distances ie. city driving, but out of a full tank i can only get 300km why this? i would think i could get more out of a full tank.

-My car is 4 speed auto with tiptronic, when im driving along and im on a hill or something ill stick it into neutral (normally to save fuel) and then back into D when i need to pick up speed again, is this ok for the transmission and gears etc? or am i damaging it?

-Finally, when im stationary at traffic lights or something and i want to pull away fast i use the tiptronic, so floor it and when i push it forwards to change into second, the engine revs very loud it judders and jerks alot and then changes gear, am i just timing it wrong or is it something else? (p.s i do have a manual liscence and can drive a manual so i know when to change gears etc)

cheers,
Sean

mmm u should be getting alot more than 300km a tank my 00' tj exec gets constant 550km tank city driving and i drive the think to the max half the time....
u wont be damaging the transmission by dropping it into neutral when coasting down a hill but not a good habit u don;t have any control of the car if something goes wrong ure up that creek without a padle and u will be putting more strain on the brakes.

the shuttering and the massive reving out is not good... when was the trans last serviced??? what colour is the oil?? and is it the right type???

for the fuel consumption check the O2 sensor, or lift your right foot slightly.

I get 500+ km out of a tank with a blower and 180+kw atw.

does the transmission have a problem when it shifts by itself, or is it only when in tiptronic mode?

When you say 300km out of a tank that really doesn't mean much. How many ltrs does it take after you have done 300km? Most Magnas the fuel light comes on when there is still about 20 ltrs in the tank. With city driving in 300km you should not be using more than about 50ltrs maximum and driving carefully with good traffic flow it should be closer to 40 ltrs. On the highway in 300km anything from 30-36 ltrs would be normal.

How many km on the car? Has the auto been serviced? Does the fluid look brown and smell burnt?

Cheers,
Alan

Putting the car in neutral when coasting down a hill will actually use more fuel not less. When in gear, the wheels spinning will keep the engine running, when out of gear fuel will be needed to keep it running. Just leave it in gear/D.

Putting the car in neutral when coasting down a hill will actually use more fuel not less. When in gear, the wheels spinning will keep the engine running, when out of gear fuel will be needed to keep it running. Just leave it in gear/D.

i 2nd this. i used to put it into N while coasting... however i noticed that my instant fuel /per 100km went up to about 2.1L/100KM. however when in D my instant fuel usage is 0.1L/100KM

good driving practice is to drop the engine down a few gears to assist in slowing and taking the stress off the brakes until you really need them. Might well save your skin one day

In some states it's actually illegal to 'coast'.

BTW Can I ask if you have a manual licence.
It seems nowadays, they teach you how to go, not how to stop. Not wanting to single you out, it's an issue affecting generations.

id check my trans fluid and air filter... both are relative to fuel economy.... if in doubt chuck it out
if the car is sitting between 150 -200k then check your o2 sensor... engine at op. temp & 2000rpm sensor should fluctuate between lean and rich every 300ms (best done with a scope/scanner)
if you are ding alot of shorts runs and the car is not being allowed to warm up then this could also be part of the problem
do you have a trip computer? if so what are your av.speed/time/av km/h/fuel used

wow cheers for all the replies, in total its done 75,000 and its had regular servicing. Im not sure about when the transmision was serviced i dont know anything about cars so ill get a mate to check it out from me. Yeh when im not in the tiptronic gear changes are very smooth, only when im using it and trying to speed away from lights it seems to judder and rev a lot. On the trip computer it does 16L/100km, all the other readings seem out of whack though because ill be riding on half a tank and it tells me i got 75L left in the tank (maybe something i should have fixed?).
Thanks again for all you replies, its been very helpfull.
Cheers,
Sean

Does the TL/TW have a fuel remaining feature or is this a TJ feature. mmmmm

Does the TL/TW have a fuel remaining feature or is this a TJ feature. mmmmm

I'd have thought TL/TW would have same or similar trip computer functions as TH/TJ. TL lost the outside temp display through a cosmetic update of the console panel, but can't see why the trip computer would have changed at all - just got that crummy little LCD display in the cluster, rather than the centre-display nice and large and up-high near your sightlines. (I have a KJ and a TJ series II, can you tell I like the centre-display?). :hmm:

Trip computer is basically the same accros all the TJ's and Tl's. It reports on fuel USED, not remaining, since its last reset

Ok i took the car in and got a mate to service it, we put on a new O2 sensor, changed the oil and filters and put 3 new spark plugs in (cheap copper ones), also bought 3 platinum spark plugs for the back (under the cam/drive shaft i think?) but he said it was a big job to take it off and put them in so im gonna keep them and put them in for the 90,000km service (cost about $100 for the 3 platinum ones). He also said i should use premium fuel so im gonna start using that and hopefully ill get mileage out of my tank.
Cheers,
Sean

My TL also gives a "range" reading on the trip comp.
gone fishing - the rear plugs are under the top 1/2 of the inlet manifold. Not that hard a job to do.
when you are shifting manually are you backing off the throttle when you are shifting? My TL is an Awd and it definately shifts faster and smoother on the upchange when left in auto as against shifting manually. I find I can control the shift a bit by using the throttle as well. Keep the throttle down and it will hold the gear longer, ease off as if you were changing in a manual and it will change earlier. Corners a lot better if you downsift manually and get the power on early but thats an Awd thing.
bollie7

Mate - maybe I'm just being an idiot by saying this - but are you sure that "juddering" isn't just your car struggling for traction or traction control trying to stop the wheelspin when you plant it? Remember when you get off the line you gotta ease into it (even when you're trying to go fast) if you plant it straight off the wheels get a huge amount of torque/power being shoved into them and all you're getting is serious wheelspin as it the car hadn't had a chance to disperse and get a good amount of traction. Can you tell me mate what conditon you're tyres are in and what type of tyres they are? I know with my old car, with a manual if I planted it straight off (we all learn eventually not to do it) it would jutter because the traction control kicked in and applied the brakes in a jerky way which stopped the wheel spin but made the car jutter bad!

With the Neutral thing - I will agree with the rest of the posters, keeping it gear it is a much better fuel saver, as the wheelspin actually turn the crank meaning the engine doesn't have to push out any power verses neutral where it has to do standard procedure of keeping the cyclinders and crank turning at set idle rev.

With fuel mate 300km's out of a tank is excessive fuel consumption if you're talking about a full tank. What would mean that you're using 20L/100km LOL! I reakon that is definetely a faulty sensor, no un-severely modded car unless its a 66' charger should be using that much fuel!! Good luck with it hope you get the issues sorted.

Ok, with the rear plugs i think im just gonna keep them and put them in when its due for its 90,000km service, with the shifting; i tend to back of the throttle a little but im not gonna bother using it anymore. When i put my foot to the floor the wheels do just spin (sometimes fun to do when its wet) but if i want to get max speed when pulling away i normally put it 3/4 of the way down so it can grip then just floor it after that. I have also stopped coasting in neutral so that should help me save some fuel too. With the new sensor in, and the premium fuel im using i should start getting better mileage. Ill keep you posted as to how it goes.

Thanks alot,
Sean

Traction control on any Magna is done by reduction of engine torque, not by wheel braking.
Replace those spark plugs now, if they are platinum plugs, you won't be doing it again for 80k kms, so no need to wait for the next service. It's an easy 1 hour job, no need to remove teh entire intake, just disconnect throttle cable and throttle body to air filte rhose and tilt teh manifold up and over to passenger's side of the car. A 3/8" drive socket set will allow you to comfortably get the plugs out in this position.
I believe your trip computer is screwy, you should record teh fuel you fill up with (in litres) and compare it to your trip computer every time you fill up for a few weeks, to make sure you actually have a problem.
If you do have a problem, most of it has been covered, O2 sensor is a big killer of fuel economy, as is a bad coolant temperautre sensor, restricted air filter or clogged/ damaged exhaust system.
Shifting into neutral on an auto is not good for it at speed, when you re selsect a gear coming out of neutral, you have lots of clutch plate slip. Let it coast, the computer will cut fuel on the overrun if you let throttle return to idle and leave it in D.

Regards, Andrew.