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I filled up on Ultimate (as usual) and added Wynns Injector Cleaner.

Will post results.

Unless my last 1/4 tank lasts way longer than i anticipate, my fuel economy hasnt improved.

i'm looking at prob just over 300km for this tank till it shows just above empty (50L since last fill).

that's a craptacular 16L/100km. wtf?

no freeway driving, all city, short trips, and plenty of boosting.

Edited by Munkyb0y
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man..

how do you guess get so many ks?

i average about 300K for a tank..

and all i got is exhaust.. stock everthing elese..

what's wrong with me car?

how low do u run your fuel gauge? do u let the fuel light come on before u fill up? if not, try that nd see how many more KMs you get off a tank.

In my modified 33 (exhaust/cooler/pod/venting bov) i used to run it ti just under the 1/4 full line and get 300kms, if u run it to fuel light, u will get close to 400kms.

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how low do u run your fuel gauge? do u let the fuel light come on before u fill up? if not, try that nd see how many more KMs you get off a tank.

In my modified 33 (exhaust/cooler/pod/venting bov) i used to run it ti just under the 1/4 full line and get 300kms, if u run it to fuel light, u will get close to 400kms.

i run mine till just above empty, but then when i refill it takes 45 - 50 litres.

example, i got 310km on 47Litres (the amount i had to pump to get back to full tank).

that's about 15L/100kms. not too good. ppl here are reporting 11L/100km.

of course if i was doing freeway kms, it would probably be alot better.

anyway, that's the most accurate way to check.

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After I put in my highflow cat my fuel consumption has dropped to 10.2L/100km. At the pump it was 440 km of 45 liters with the gauge sitting just below the 1/4 mark. A fair bit of that was freeway to and from uni but I give it a squirt whenever I"m urban driving.

Gotta love the little rb20 :)

Have you checked things like fuel pressure, o2 sensor, injector flow test and crud in the exhaust?

Theres no reason why mildly modded engines wouldn't be able to run close to the factory specs. You just have to keep eliminating things till you get it right.

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o2 has been changed. made no difference. but i gotta say, freeway kms make a big difference. i got 380k's off a tank, where 200kms of that was on the freeway. and that's with plenty of boosting.

hmmmm, exhaust, never thought of that. i've got 3inch turbo back. my mechanic told me to try the temp sensor. but u know how it is, all these sensors cost money, and alot of the time, nil results.

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o2 has been changed. made no difference. but i gotta say, freeway kms make a big difference. i got 380k's off a tank, where 200kms of that was on the freeway. and that's with plenty of boosting.

hmmmm, exhaust, never thought of that. i've got 3inch turbo back. my mechanic told me to try the temp sensor. but u know how it is, all these sensors cost money, and alot of the time, nil results.

The ECU only uses the o2 sensor when your cruising. As soon as you hit boost or get the revs too high it'll run rich again. Your best bet is probably a tune, they run rich from stock and its probably worse now you've modded it. If your AFR's are around 10-11 instead of 11-12 your going to be using more fuel and making less power.

The temp sensor shouldn't make a difference, as far as I know the ecu just uses it as a warning signal. It might run overly rich if the light is coming on to reduce the temperature, but unless the light is coming on I don't think it'd be causing anything.

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The ECU only uses the o2 sensor when your cruising. As soon as you hit boost or get the revs too high it'll run rich again. Your best bet is probably a tune, they run rich from stock and its probably worse now you've modded it. If your AFR's are around 10-11 instead of 11-12 your going to be using more fuel and making less power.

The temp sensor shouldn't make a difference, as far as I know the ecu just uses it as a warning signal. It might run overly rich if the light is coming on to reduce the temperature, but unless the light is coming on I don't think it'd be causing anything.

so how do u tune a stock ecu? with no safc etc?

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if you wanna improve your fuel economy a safc2 is the was to go, i went from 180rwhp and 380ks to a tank to 215rwhp and 420 to 450k's / 50l. and that was with increasing boost from stock to 10psi.

this is what makes me worry. you were getting 380kms from 180rwkw before safc.

i'm only getting 300kms from practically stock (3"exhaust, pod).

cleaned afm, changed 02 sensor, new plugs, car runs fine.

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  • 3 weeks later...

I Just filled up my car for the first time with the rb26 in and only got 235 kms out of the tank!!

i was shocked my fuel consumption halfed from the rb20. Im still running it in so i wasnt thrashing it. Im running a microtech ecu, is something wrong? do i need to retune or is this the reality of an rb26 running 310 rwhp ?

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I just tried some injector cleaner and it seems to have given me a few extra kms. I used to get around 400-420kms before the fuel light came on but yesterday i reached 490kms (r33 gtst)! I used redline SI-1 fuel system cleaner. I also changed the sparkplugs recently so maybe that helped too. anyway im pretty happy with the results as my previous car used to only get me 400kms from a 50l tank and that was a 1.6l!

Haha looks like that was a one off cos ive been getting around 400kms since. Oh well....

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Unless my last 1/4 tank lasts way longer than i anticipate, my fuel economy hasnt improved.

i'm looking at prob just over 300km for this tank till it shows just above empty (50L since last fill).

that's a craptacular 16L/100km. wtf?

no freeway driving, all city, short trips, and plenty of boosting.

Yea I am about the same as you - but I do have an auto so I guess I'm going to waste a little more fuel anyway. Still sucks though :(

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