Anyone got any real life experience with remaps and MPG?

[Konan555]

I've got the chance to have a bit of a tweak to the ole map. Reading around, a lot of tuners claim better MPG as a result (subject to normal driving).

I'm pretty sedate as it is during the commute. 250 miles a week, the only way I can really keep the thing running is to change up nice and early and go light. Still, regular 33mpg from a WRX impreza is something most people claim isn't going to happen

Going to get the big service done soon, which will involve a RR health check as part of the deal. There's also room to have a remap done. What I can't afford is for the fuel consumption to rocket. This question has been raised on many a Subaru forum, but invariably runs into a wall of "you've got a Subaru, you idiot, stop trying to make it economical"

Anyone had a light remap and lived to tell the tale?

[ehhhhhhh]

...but invariably runs into a wall of "you've got a Subaru, you idiot, stop trying to make it economical"

They have a point tbh. if you start to worry about your impreza's thirst then it's time to sell it

[Konan555]

They have a point tbh. if you start to worry about your impreza's thirst then it's time to sell it

No, I'm worried about making it worse than it is. As it is, it's fine. It's 50% better on fuel than what I had

[roachcoach]

One comment I read, which I believe to be very true was: "No matter what a remap does on paper, your mpg will drop because you'll start booting it everywhere"


OT: Not a bad mpg though for that, I'm getting about that with my ASBO, although the novelty value hasn't fallen off yet so its not what it should be, reckon I could get a solid 35 out of her, but I have a very kind commute for fuel.


Edit: I guess if the worst comes to it, can't you reset the ECU yourself if it does bugger the fuel?

[Konan555]

OT: Not a bad mpg though for that, I'm getting about that with my ASBO, although the novelty value hasn't fallen off yet so its not what it should be, reckon I could get a solid 35 out of her, but I have a very kind commute for fuel.

You refer to the ST? I think the 2.5 runs at a fairly high CR for a turbo, certainly higher than the Volvos. Should help in the MPG department, even if it reduces some of the 'easy gains' the Volvos got when it came to doing some fiddling.

[roachcoach]

Yeah, MPG is a hard beast to master in that car. Need to be very gentle, literally the act of wiggling my big toe in thin soled shoes (i.e. enough to change pressure very slightly since I usually have the ball of my foot on the pedal) will drop the instant reading from 35-40 down to 20-25

Gentle roll to work at 50-60mph depending on traffic will see 40-45mpg (Its fluctuates) steadily on the flats. Basically though, the minute you stop trying to max mpg it drops to about 25-27mpg. Perhaps interestingly, being a hooligan aside, it will maintain that mpg from about 30 to...uh...lets call it license losing speeds...so in some respects that's good I guess

Overtaking in a hurry, however, will see about 6-8mpg...


Love her though, beautiful machine and certainly not complaining; anyone complaining about fuel 'economy' in a turbocharged 2.5L petrol needs their head examining imo.

Anyway, no more derailing from me.