Well at least my timing was

I just filled up my 1-week old 2005 S2000 for the first time today. I have almost 300 miles on it; only 300 to go until I can break the sacred VTEC threshold. I got about 23 mpg, so I'm happy with that at least.

I went to Costco and put in 93 Octane (their high-grade) and when I took off I noticed an almost immediate increase in the smoothness of the engine. I think the dealer put in regular (87?) when they filled up the tank.

I was wondering why the car seemed somewhat sluggish (besides the fact I couldn't rev it past 5500rpm), but now I think I know! Dumb dealers

Do you think it was my imagination, or is there a noticable performance difference between the different grades of gas?

 

Obviously yes... 11.1:1 says it all.

 

it was in your head.. it wouldn't be a "almost immediate" increase, it would take time for your ECU to realize the higher octane gas

 

He's had the car for a week...... time? ECU or not, the fuel still has to go to the engine. Running a higher octane fuel would no doubt change how the engine fired. Now, whether or not it was immediatly noticable is a little more doubtful, almost immediatly - probably. Lets not forget there still would have been lower octane fuel in the line. If you understand what an octane rating is (not saying you don't), this should make sense.

 

won't rev past 5500?
here's your sign

 

Read his post again, he can't do it. He only has about 300 miles on his car, brand new. So he's taking it easy until the break in is over.

 

Then i take it back, thank you for correcting me, slasherx

I was under the impression that the engine is running a little "limp" with the regular gas (87). then when you introduce premium (91 for most), the car will run a little rich, which the ECU senses, then advances the timing to make up for the higher octane

 

Well it wasn't immediately immediate. It was slightly immediate

I noticed it after about 5 minutes of driving when I was merging onto a highway. There was noticably more pickup and the exhaust-note was a homogenous tiger's growl (versus the graceless burbled cacaphony I had noticed for the previous 300 miles).

 

No problem, didn't mean to sound like a prick either. I'd imagine the car would run like a limp noodle on 87.