Hello all,
Do any of you know if putting 100 octane gas may hurt my engine. I may want to do it once just to get a cheap thrill out of my car. The Moroso speedway is on my way to work (well, almost) and they have 100 octane there. I thought I check before I do something potentially stupid.

 

Yes, 100 is fine to use. Anything above that on a NA is probably not a good idea though...

 

haha, that reminds me.
on my way to Los Angeles, i was running on empty and i wanted to try that 100 octane gas at the 76 Gas station over by Calabasas. I was going to fill about 5 gallons 100 and the rest 91. well, as i was fueling the 100, a guy comes up to me and starts talking to me about my car and how nice it was and etc... next thing i knew it... :CLICK: turn around, full tank of 100 octane at about 70 bucks. WTF!!! dammlt... lol

 

^ haha Didn't even know we had 100 octane here in Cali. How'd it ryde afterwards?

 

to be honest, it felt the same

 

So? how did your car run after that? Any unwanted consequences?

 

Ahh, I am not going to waste my time or money then. Thanks.

 

hahaha thats focked up....

 

looool samething happened to me at the speedway. I wanted to try the 100 octen, so i filled it up with full tank trying to get good numbers but my car got havier over there

 

Do any of you know if putting 100 octane gas may hurt my engine. I may want to do it once just to get a cheap thrill out of my car.

LOL and what cheap thrill do you expect to get from 100 octaine? Certainly you won't detect any performance increase.

 

To get the thrill you would also have to increase your compression in some way to take advantage of the low volatility of the fuel. Check the compression ratios of some single engine private planes and you will understand why aviation fuel is high octane.

The common misconception is that "super" or "premium" will make the car more powerful. It doesn't. In fact, the lower the octane number, the more volatile the fuel and thus, the faster and more powerful burn rate.

All that said, the above is contingent on the compression ratio of the engine, either by piston crown, FI, cam and valve size and timing, etc or all in combination. High compression needs high octane to mitigate the pressure and vice versa for lower compression. Finding the perfect balance is really the answer. You want the fuel to burn, not explode.

 

THANK YOU!!!

 

what octane gas do u put in ur car?

 

With a static compression ratio of 10.3:1, whatever good quality high octane pump gas you can get is your best bet, typically 91 to 93. In Texas, 93 is readily available and I use Chevron or Texaco exclusively.

You could go lower but and the engine's ECU coupled to the detonation sensors will compensate by retarding the timing and thus, decreasing the power output in favor of protection.

You could take advantage of 100 octane by reflashing the ECU to a more aggressive timing curve (advanced). You would still want to strike a good balance because even with the right fuel, there is such a thing as too much advance. I bet the right balance could yield another 20 ponies or so but then you would be stuck with using that fuel.

 

^^You've got me considering dropping from 93 octane to 91 octane to save dough. It's usually $0.10-$0.15/gallon cheaper for 91. Do you think there would be any noticable difference in performance with a measly 2 octane difference?