I have just purchased a WRX sti. My fuel gauge can be seen visible dropping while driving hard over a coulple of miles. The car an 02 sti puts out 339bhp and has the usual basic mods, ie Pump, remap, decat, exhaust etc.

Is this normal and what sort of MPG will I be getting with careful and hard driving?

Cheers.

 

Screw the MPG Drive, enjoy and fuel up when you need too. These are not green eco warriors

**** all to mid high 20s per gallon

 

Just do a calculation based on refilling a pre-filled tank, knowing the miles you have done. 4.54 litres to the gallon. Mine's similar to yours and I average 19-20 mpg.
dnc

 

eeeerrrrrrrrr dddddddddrrrrrrrrrrr its a impreza with 300+bhp the fuel gauge does do that come on you didnt expect it to be good on fuel did you ha ha ha ha ah ah perhaps you should have bought a diesel astra or summat

 

339bhp and you're complaining about fuel consumption??!! You're in the wrong game!!

I can see my needle move on a hard run and thats in a 260bhp wagon!! What I would give for 340bhp!!

 

mines 300bhp and I can see my needle move I'm constantly filling her -she is far from economical but such an awesome car to drive - cant have cake and eat it

 

320bhp
and im getting 23 to the gallon


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Ok i lied

get a life thats what you bought the car for lol

 

when i had mine re mapped and done up i couldnt belive it ether but got used to it after a few hours i just worry about how to wipe my smile off my face when been out for a run

 

i thought remapping helped improve economy?

 

A re map would only improve fuel consuption when on a light throttle/cruising.

If you are going to use those horses, they need feeding i'm afraid.

 

you can say that again

 

How does your motor make 339bhp?... Seeing as the cc's and rev limit are fixed, then, when at WOT, it has to have bigger 'explosions' to achieve this greater power i.e. more fuel/air added for any given 4-stroke cycle.

Because of the extra air added via the turbo's upped boost - in effect, persuading the engine to be 'bigger' than what it is (depending on the boost level) - then this is the reason why forced induction engines are v. thirsty at WOT (despite, in the case of the Impreza, its relatively small cc's).

 

As said already, don't expect to be able to use 339bhp and get good mpg..

My wrx puts out c350 and averages around 22 with mixed urban driving and no doubt if I drive harder more often it would be less ~18. however on a recent family holiday to the north Yorkshire Moors (600 miles) I drove 99% off boost and was astonished to return nearly 32mpg..! I'd have never believed it if it hadn't done it myself..!

It's all down to how heavy your right foot is. A boost gauge provides an excellent guide when you need to keep things economical..

 

spot on that

 

400 bhp on track = 6 mpg....

Average road use sees 22 mpg, down to 14 mpg on a "club run"....

ENJOY !

dunx

P.S. At 2 bar of boost you are running a six litre engine ! ! !

 

That's right!

So in dunx's example above...

3bar in total.... 1 bar of air pressure is what a normal N/A engine would ingest (so a F.I. engine would also get that 'for free' anyway)... But the remaining added 2 bar provided by the turbo is therefore equivalent to having another 2 Impreza engines' worth of capacity... so 1994cc x 3! (just under 6 litres).

 

never thought about it like that - it certainly explains the rapid draining of the fuel tank!

I've got a standard(ish) V4 sti and average between 25-28 mpg, but I did get 33 mpg on recent long motorway trip which surprised me a lot. If driven enthusiastically it does drink a lot more tho - all about smiles per gallon after all