R34 Gtt - Chewing Up Petrol

[Swole]

Hey everyone,

Finally decided to create a thread asking why this is the case with my car.

The main point being - it's eating up a lot of petrol.

This is my first car which is turbo, and I realise GTT's consume more petrol then N/A's.

But the tank before I filled up, I only got 261km's out of almost a full tank.

From what I've heard, that's far less then average.

Any reason why this could be?

Seeing as this car is my baby, it's rarely driven let alone thrashed.

Cheers.

Edited November 4, 2013 by Swole

[Dose Pipe Sutututu]

Several things come to mind,

Dirty afm

Faulty water temp sensor

O2 busted

Atmospheric bov

Intercooler leaks

[Ben C34]

Lots of short trips......

[Swole]

Lots of short trips......

Nope, drives usually go for as long as cruises (because they generally are cruises), probably between 1-3 hours.

Got told that the car may have been tuned to consume more petrol and if so I should get it retuned?

Several things come to mind,

Dirty afm

Faulty water temp sensor

O2 busted

Atmospheric bov

Intercooler leaks

Unsure of what half those mean but I'll definitely ask some mates.

Cheers.

Edited November 4, 2013 by Swole

[jjman]

a tune shouldn't make a car chew more fuel unless you are really relentlessly using the extra power that a tune has unleashed.

otherwise, that kind of fuel usage certainly points to an issue somewhere and the solution is bound to be in the list mentioned above.

take it to a reputable shop that knows skylines and get them to go thru the list testing the various components.

[blind_elk]

But the tank before I filled up, I only got 261km's out of almost a full tank.

How much fuel did you put in to fill the tank?

Driving style is always a big contributor to fuel economy - good or bad. If you consistently use boost, you will get crap economy. Unless you can CRUISE - on a constant throttle - the O2 sensor will not play any significant role in getting good fuel economy. City driving, or any form of on/off throttle driving, is not conducive to getting the ECU to pay any attention to the O2 sensor. If you let the engine warm up before driving anywhere, then of course you will get crap economy - burning fuel to do no distance doesn't make sense.

[34GeeTeeTee]

No matter how hard you drive a stocky R34 it should not get that bad in terms of fuel economy which indicates there is a problem.... I have had my car tuned from semi stock all the way through to where it is now and it hasnt been that bad on fuel even on ethanol.... Take it to a reputable tuner or mechanic and get it sussed out as you certainly have a problem

[Swole]

How much fuel did you put in to fill the tank?

Driving style is always a big contributor to fuel economy - good or bad. If you consistently use boost, you will get crap economy. Unless you can CRUISE - on a constant throttle - the O2 sensor will not play any significant role in getting good fuel economy. City driving, or any form of on/off throttle driving, is not conducive to getting the ECU to pay any attention to the O2 sensor. If you let the engine warm up before driving anywhere, then of course you will get crap economy - burning fuel to do no distance doesn't make sense.

45L before that tank, then 49L after using it.

No matter how hard you drive a stocky R34 it should not get that bad in terms of fuel economy which indicates there is a problem.... I have had my car tuned from semi stock all the way through to where it is now and it hasnt been that bad on fuel even on ethanol.... Take it to a reputable tuner or mechanic and get it sussed out as you certainly have a problem

Yep, already got a couple mates who are mechanics to check it out.

Thanks for the responses.

[MrRx7s3]

You're lucky, I get 180-200kms out of a full tank of V-Power and the only mods I have are a front mount, exhaust, 12psi boost on stock turbo, tuned to 215rwkw with a power fc, it's got a new 02 sensor, I cleaned out the AFM not long ago, new set of plugs, only thing I can think of is the exhaust leak I have at the moment but I don't think it should be that much.

[Chris32]

Jesus! I get around 460-520kms a tank, around 50L if I fill it up when the light is on.

I'd be checking your O2 sensor

[Charles89]

I was getting around 13.8-14.5L per 100km with my GTT, 12psi, exhaust, nistune. Changed o2 sensor, afm, fuel filter, spark plugs (1.1mm gap), all did nothing... Then I noticed the car idles a little rough, so I re-gapped my plugs to (0.9mm), clean AAC valve and reset the ECU, car idles a lot smoother and now can do about 12.5L per 100km and thats city driving.

[Blackkers]

Woah @mrrx7 time for visit to the tuner, might even save you some coin in the long run

[Missileman]

Also if someone has put a low temp thermostat in, or yours is stuck open, then that will also add to poor fuel efficiency. Cold crank enrichment tapers off at 70C so the quicker she gets up to temp the better.

Edited November 12, 2013 by Missileman

[MrRx7s3]

It's been like that always, when it was stock and after the tune, I do do alot of short trips, I'm running PFR8 plugs with a 0.9 gapp, car idles smooth, but you can farken smell the richness when I come to a stop or idle.

[MrRx7s3]

I was thinking of cleaning the AAC valve would that do anything, is it the same process as the r33 tutorial write up? Would the exhaust leak be causing it aswell.

[MrRx7s3]

Ohh and I'm also running yellow jacket coilovers.

[Charles89]

I was thinking of cleaning the AAC valve would that do anything, is it the same process as the r33 tutorial write up? Would the exhaust leak be causing it aswell.

Yeah, basically the same, but you need to disconnect 2-3 coolant hose up the top, and you just need to quickly bleed the system after you put the AAC back together by loosening the bolt and start the car and then when coolant start coming up, tighten the bolt and your done. It looked/sounded difficult but it's very simple.

[GH05T]

even on my 4wd stag i expect 450-550 km from a tank. my GTT was better than that.

[Plattsy]

id both be changing you rthermostat and 02 sensor. 100 bucks. if it works great, if not, you have two new parts that you know are fine. 02 sensors are meant to be changed every 40k and most have the original factory one in.

[Missileman]

exhaust leak pre turbo will have more affect on spool and boost and only a small effect on fuel consumption, a boos leak after the turbo will have a big effect on consumption.