I can only think of two places in my surrounding area that sell 91 octane gas. I run 93 all the time, but I remember reading that you should run what the manual says.

I'd imagine it's not a big deal, but would 91 run more efficiently? Could I do something to utilize the better gas, like raising compression. Maybe I could get a valve adjustment, and while I'm at it grab a thinner head gasket?

Or should I just shut up?

 

Raising the compression on lower octane gas is not advisable. You should be fine without making any changes, the computer will just back off the timing accordingly.

 

Maybe that wasn't clear, I'm sorry.

The car requires 91, per the manual. I'm only able to get 93 on a regular basis, so that's what I put in.

I feel that if I'm putting in better gas than necessary, there's got to be something I can do to take advantage of the extra 2 pts. If I was turbo, I'd raise boost.

That make any sense, it's been a long day.

 

It doesn't hurt to run higher octane than recommended, the recommendations are viewed as the minimums. Personally I wouldn't worry about trying to raise the compression to utilize that extra 2 octane, although if you had a fuel computer you could tune to make sufficient use of it

 

Wow, somebody's actually complaining about having 93 instead of 91? Around here the highest octane we get is 91, unless you go to the one 76 station in town that sell 100 octane "competition" fuel.

 

I'm not complaining about having 93, but about not utilizing the extra 2 octane. I've come to terms with it now though. hehe.

I was considering an Apexi V-AFC first, see if I could extract any ponies that way. Mainly buying it in preperation for I/H/C/E, so I could tune as I go.

Would that be a decent idea?

 

It's a completely decent idea.

 

I've been using 93 octane since I bought my car. The next grade down was 89 and I promised myself I wouldn't put that in it.

 

good job! you could advance the timing a bit, you might find a few extra ponies there, but you'd have to listen for knock under normal driving conditions, do you know how to do that?

 

Wouldn't matter if he did, OBD cars have computer controlled timing, no adjustments.