pro-slug 2003

I was just wondering if our cars will benefit from higher octane gas in the stock form. Say if u resett the ecu and add super or premium to it will the ecu adjust to it. For instance will it take advantage of the better fuel and change the ignition timing. I know the wrx ecu is very sensitive and u can lose 20 horsepower when u resett the ecu and it will relearn while u drive the car and gain back the power after some miles.

R2Di2Dc2Do

Not flaming, but have you done a search. And i believe the answer would be no.

UCSBgeek

I'm afraid not... I don't think there is a knock sensor on your car, so it's not going to advance the ignition timing.

UCSBgeek

you know, I could be wrong. the 2.0 liter engines may have a knock sensor... theoretically you should get the same performance on 87 ... though you may get something out of 89 ...

http://www.protegeclub.com/forum/sho...&threadid=1022

Nevertheless, it's not really gonna give you that much notable of a difference, the WRX is a turbo car and the power levels can change significantly based on the quality of the gas (it is DESIGNED to run on 91 octane, after all). The Protege is designed for 87 octane...

toucci

we've been getting around 30 mpg at 70-75 mph on the freeway. if you go 80 it drops to 28

in the city its about 25

this is on 87 octane, never 85 like we found out in the middle of nowhere

Redfyre

Here's my experience over the last year and a half with higher octane gasoline:

I've noticed slightly better fuel economy with a 91 octane gasoline in comparison to an 87 (which our cars are designed to run on). I do a lot of highway driving and at speeds above 120km/hr that fuel economy is about the same as 87 fuel or maybe 10km better. At speeds between 100-120km/hr that fuel economy is bettered by about 10-20 kms.

But I have notived no improvements in throttle response or hp (like I'd feel 1 or 2 hp anyways).

In my opinion the extra money I've been paying for 91 octane is not worth it.

Also, I have an article on premium fuel if you wish to read it. I'd attach it but I don't know how so PM me if you want it.

Rick Hart

I have noticed a significant improvement in both mileage and power when runnung 89 or 90 octane gas in the summer, but not any improvement in the winter. I suspect the higher octane gives the knock sensor enough latitude against the hot incoming air so it doesnt have to retard the timing to stop the knock.

RH