The short story:
Got some bad gas in my WRX (87 or 85 Octane) and it drove like crap. Couldn't build boost for anything and got HORRIBLE gas mileage (20mpg highway). As soon as the tank was low, I put in 91 Octane and slowly richened out the tank.

What sort of bad things could have happened from this?

For the lazy, you can stop reading now

Long Story:
I shipped my car from Hawaii and had a company pick up my car from the dock and bring it to LAX. I paid them $15 extra to put PREMIUM gas in my WRX. (I run a 93 Octane map from Cobb, but I figured 1 tank of 91 would be OK).

I got in my car at LAX and found the bastards had taken my cigar punch from my keychain, but I got over it. I startred driving and noticed that the car was a little sluggish. I just figured it was crappy Cali 91 Octane. I took it easy on the throttle, stayed out of boost for the most part and made my way into Nevada before I filled up. After I got some 91 Octane in my car I noticed a MARKED improvement. I also noticed that my gas mileage (even though it was all highway miles) was equivalent to city driving. I got roughly 20mpg on pure highway driving. Hmmm... something seemed not quite right.

After filling up again in Utah, I discovered that my car was getting more and more responsive and getting better and better gas mileage. By the time I got out to the midwest and real 93 Octane, I was getting 31 mpg highway driving and good boost again.

I've been driving my car for a couple of months now. I reset my ECU a few weeks back and noticed that after the Vishnu ECU-tuning trick My car is running well again.

Any thoughts would be appreciated.
-Etch

 

Sounds like you figured it out on your own. Any azzwipes that would steal stuff, certainly wouldn't give a crap about the quality of gas they put in your tank.

You prolly detonated lightly a bit and the ECU corrected by temporarily cutting your cars ***** off. Once you gave it its octane fix it was happy.

jason

 

Actually, I bet it detonated a LOT. For a few seconds, then the ECU doused the flames with lots and lots more goat pee that was passing for gas (heh, that's funny) while pulling timing. And even the 91 that you put in would still have caused detonation on the 93 map if the ECU hadn't still been compensating for the 87. But yeah, you figured it out.

 

no, kevin, it says FROM: not EMPLOYMENT:

and, Etchy, i give you 5 to 6 more days before your pistons shoot out your spark plug holes. you're totally screwed.

 

First of all, Tim, I'll write whatever the hell I want to there. You're not the boss of me.

Second, his motor is fine now that he's back on 93. One tank won't kill it since the ECU compensated for it by becoming a boost ****.

 

But can the ECU completely compensate for it? No damage done at all?
...and you guys sound like you're in kindergarden

 

Thanks for the response. I've done enough reading to realize what happened, but I wanted to get some good opinions for this particular problem.

Thanks for posting on a Saturday.

 

Yes it can, with none at all, and shutup, you're a stupidhead!:banana:

 

real mature, buttface...it was my understanding it couldnt completely compensate for extremely low grade fuel...dont know where i got that from

 

The WRX owners manual states that 87 octane gas can be used temporarily, if 91 octane is not available. Here is how Shiv Pathak of Vishnu Performance explains what happens if you must run the engine with 87 octane.

--
0==WW==0
"…axles of evil…" - george w. bush

 

I didn't hear any pinging, but I'm not sure what to listen for. Thanks again.
-Etch

 

I kid, i kid. But I do appreciate your contributions to the forum.