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Hey guys, I have a few ideas already but throw some at me.

ATM I'm getting 320ish a tank.

Mods are simple, fmic, boost tee with gauge, running 10pound with 3" catback system

Thinking of doing the 02 sensors first.

Cheers. ~ash

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try getting some contact cleaner and cleaning the afm ( if you have one). I had the same problem when i first got my 33 and by changing the sensor and cleaning the afm im getting a lot better fuel economy

how about you tell us how many litres you are classing as a "tank". that will give us a better idea of whether your economy is just ordinary or extremely crap.

also, what sort of driving are you doing (city driving/highway driving) and how do you drive? if you do city driving and boost it often then you will get pretty crap fuel economy and no amount of changing sensors will help much.

Highway driving mostly.. I don't boost like an average wanker, i don't see a need in showing my car off to the 5-0 :P

I haven't tuned her yet, she's due when the money is here, so no management.

300ks to a full tank which is 40lts

ill do the afm and the throttle body when i get the 02 sensor in.

Cheers

40L isn't a full tank.

~13.33L/100ks, is not great, especially for highway driving. It is a skyline though... I get about the same but mostly driving in traffic.

sensors may help but even the minor mods you have done will mess with the factory tune somewhat. You're probably going to need a proper tune

yeah as above, 40L is a long way from a full tank. skylines have a 65L tank. you should have about 10L left when the fuel light comes on.

as for the economy you are getting, yeah that's pretty ordinary economy for highway driving. i'd start with your o2 sensor as that is responsible for altering the mixtures at light throttle. getting a tune won't help too much on highway driving (if the ecu you use still reads from the o2 sensor). you can check whether the o2 sensor is working correctly with a multimeter, or a consult cable.

it's also worth asking what size wheels and tyres you run, as that can make a noticable difference. big rims (17" and above) plus fat tyres will hurt your economy, as will running the tyre pressures too low. engine condition as well as fuel injector condtion will also have an effect. dirty injectors will hurt you economy (and a bottle of injector cleaner won't do squat), as well as a tired engine that is a little bit down on compression will also use more fuel.

If you have low compression that wont be helping, along with a stock computer which is always rich and retarded, maybe timing is out too, plugs maybe old,

a stock dump might be an issue too, i have a 3inch dump you could have $80,

i use to get about 600ks out of a tank with most highway, and that was front mount, exhaust, 10psi standard ecu

now im getting 300 on highway with a whole new setup, gt3040, full exhaust, 18psi, running wolf v500. Kind of depressing as its pretty much the same economy around town...

thats what i was thinking to, but it was the tuners prefered choice of ecu, and i let him know i was more interested in the economy for highway driving and didnt care about around town to much, I was talking to another person with same ecu tuned by the same tuner and they are averaging 550ks to a tank with more power than i am making... I just think its my car, seem to always have problems with something going wrong.

Thought I'd spend the doe and get a compression test done aswell. Booking that in with Pete at rpm.

I'm running 18" wheels with low pros federal/Heros.

I'm thinking it's bc my tank is not 65 ltr as u guys keep saying it is :P. don't ask why, it was like that when I bought her.

Thanks for the replies, several minds are better than 1 so I thought I'd check.

~ash

thats what i was thinking to, but it was the tuners prefered choice of ecu, and i let him know i was more interested in the economy for highway driving and didnt care about around town to much, I was talking to another person with same ecu tuned by the same tuner and they are averaging 550ks to a tank with more power than i am making... I just think its my car, seem to always have problems with something going wrong.

I dont think that tuner is giving you value for money, sounds like a rip off to me. I just found a new tuner and he could not believe the tune that had been done previously, no wonder the car had no top end, they had tuned it to be weak at the top.

taking someone elses tune and putting it in your computer is not a tune, thats what they can do and they know you have no idea. He should of tuned it for more than just highway. must of took half an hour that job.

Edited by SliverS2

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