i have been wondering about this..
since i bought the car about 7 months ago, i have been noticing a very faint but gradual loss of power.
since it was due service for quite a while i gave it to the dirty filters etc..

but after the service it did not get any better, in fact i think its a bit more obvious now.

i usually drive in the same vicinity, and i have been observing slower take offs, and car shifting down at hills and slopes that it didnt before.

recent things done to car
1- full service, fuel filter, oil filter, air filter, engine oil, etc
2- timing belt replacement. (200 kms ago)

after the service and belt replacement, i have also been observing slower rpm idling. idles around 400-500 range. and possibly a little bit increased fuel consumption.

recent failures
failed alternator due to accident while replacing timing belt. car broke down after i left mechs, but i was able to stop it safely and quickly.

assuming im not daydreaming,
what could be causing this? any ideas?

Could be lots of things.

Dragging brake pad(s) somewhere.
Dragging handbrake shoe(s).
Soft tyre(s).
etc.

Most likely though, it's you getting used to the car and being more careful with the throttle.

Low idle isn't normal though, should be 700 + or - 100 rpm. Could be ISC ???

my front brakes are a bit trouble.. they are noisy and dont lock properly, i will have them replaced this week.
i tend to think that they dont drag though.. when car is gliding i dont feel anything holding the car back.

just checked the tyres, they seem ok.
double checked the idle RPM, it sits on 500 sometimes slightly dropping below , and it sits at 600ish when the air con on.
engine is relatively warm. what is ISC ? remember i am a car noob :P

i also measured voltages again just now.. it has been sort of bugging me that the mech who replaced the broken regulator, didnt do anything inside the alternator.
later i noticed the medium level of corrosion and damage on the pins of the broken regulator, made me think probably the corresponding metal parts inside the regulator might not be perfect due to arcing.
but voltages seem good, 14.1 running, 12.2 on battery. not sure whether any relevant or not

i did consider the getting used to aspect.. but i am quite sure about this.
i do drive relatively aggressively and even when i push the car, i dont feel that 150kw in there..

What fuel economy are you getting?

What fuel economy are you getting?

13.5 city driving.. i used to get about 11.5 in similar driving.
havent been on long distance drive after services though .. cannot compare yet

Fuel injectors getting clogged? Also your battery might be slowly dying (strange I know but I had this happen to me - new battery = better responsiveness and restored fuel economy)

Fuel injectors getting clogged? Also your battery might be slowly dying (strange I know but I had this happen to me - new battery = better responsiveness and restored fuel economy)

i tested the battery to the best i can, (i was suspicious of it, coz when my alternator failed, it only ran for 10-15 minutes on battery)
i plugged a voltmeter, and turned engine off, put load on the battery with front lights and car stereo (quite powerful one) measured battery for about 10 minutes , didnt see a drop under 12 volts.
i dont know if this is sufficient testing..

i just inspected the last service invoice and past service from the logbook,
according to the service book, the conventional spark plugs were supposed to be replaced... service receipt doesnt say that they have
according to the logbook, the fuel filter was supposed to be replaced at 120.000 kms service.. but i do not know whether they actually did it or not.
the previous service was conducted at 120k kms but on feb 2012.
the last service was performed at april 2013.. so there is a huge 1 year plus time between these two services but only 15.000 kms.

should i have the fuel filter and spark plugs changed?
could these and late performed service be causing some clogging on injectors or something.

Fuel filter and spark plugs could contribute to this. Dirty throttle body as well.

Fuel filter and spark plugs could contribute to this. Dirty throttle body as well.

hmm.. front plugs seem to be already due.. i really wonder why the mech didnt change them during service. and fuel filter i think is quite cheap and easy to install..
its really annoying that the service book has dates and stamps from various shops but the tickboxes are not marked.. so there is no absolute way of knowing is whether the platinum plugs were replaced at 105k service..
my gut tells me that most likely the person sold the car around those kms (the girl i bought it from had it for a year, and it was at 123k) probably didnt get the plats done. the girl obviously wouldnt have them done unless car acted up..

i tend to think, that probably the platinum plugs have not been changed .. maybe yes maybe know.. its an expensive job but i am getting really fussed with the car these days.

i am thinking of getting a full set of NGK iridium IX or IR spark plugs, have them all same type and quality, and dont bloody worry about future conventional plug change for a long long while.

would this be any logical?
manufacturer's claim the iridium ones provide fuel efficiency as well as long lifetime, would having them all same be beneficial?
is there any truth behind these claims.. or just another marketing gimmick?

thank you

Factory fitment is double platinum on the rear bank, copper on the front.
I've replace all of mine (2 cars) with single (centre electrode) NGK platinums. Good for 100,000 km.
Copper ones should be changed out at 45,000 km, but in actual use they go a lot longer than that.

NGK BKR5E11 Copper 45,000 km pregapped
NGK BKR5EGP Platinum 100,000 km pregapped
NGK PFR5G-11 2X platinum 100,000 km pregapped

Spark plugs will only affect power and economy if they are misfiring.

Hi if you are going to do plugs do leads at same time save yourself time and money...I had slight flat spot , car has only 110 000km replaced leads, motor runs smooth, more power and fuel consumption went down... hope all goes well for you...
I also checked my oxygen sensor still ok.....if oxygen sensor goes your fuel goes up too

Hi if you are going to do plugs do leads at same time save yourself time and money...I had slight flat spot , car has only 110 000km replaced leads, motor runs smooth, more power and fuel consumption went down... hope all goes well for you...
I also checked my oxygen sensor still ok.....if oxygen sensor goes your fuel goes up too

hmm, dont know about the sensor, but i will see a new mechanic for my brake pads and he will check the other issues.
i already ordered the below, includes the leads. good advice.. thank you .. for those who recommended me rockauto in other threads, thanks heaps guys !!
that was a life saver, this is my third order, and the first second were shipped same day and arrived in 5

BECK/ARNLEY 0431018 (043-1018) Fuel Filter $ 13.23 $ 0.00 1 $ 13.23
NGK 7994 Spark Plug $ 9.69 $ 0.00 6 $ 58.14
NGK 55051 Spark Plug Wire $ 43.79 $ 0.00 1 $ 43.79

I avoided the Iridium plugs, as the platinum plugs were something like $2 each, and there is no real advantage life span wise. Each to his own I suppose. lol

I avoided the Iridium plugs, as the platinum plugs were something like $2 each, and there is no real advantage life span wise. Each to his own I suppose. lol

considering i will be paying 95 bucks for the labor to replace them ( i think thats a bloody good quote) i said fork it and get the best supposed one.. they re only 10 bucks anyway, and will sit there about 100.000 kms :P
i guess whether they re any good or not is yet to be seen :)
btw . double plats are same price as premium iridiums..

$2 each was for the single platinum plugs. Guess I will see how they wear on the earth electrode in a few year's time.

If you are paying for labour, you may as well go for the best.

13.5 city driving.. i used to get about 11.5 in similar driving.
havent been on long distance drive after services though .. cannot compare yet
That sort of fuel economy drop could also come from a failing oxygen sensor.

sounds to me its a TB clean time, in services, nearly all mechanics don't do this, a can of carbie cleaner, a can of Subaru and about 2 hours of your time, probably best to get an O ring seal for the idle speed control motor because that needs to come off to.