cthree

91 octane or higher is required due to the high compression of the S2000's engine. Always use Premium gas in the S2000.

Using premium gas is not for increasing performance (not directly) or for giving you extra horsepower. What it does for you is prevent detonation or pre-ignition. Detonation means that the fuel and air mixture ignite at the wrong time due to the high compresssion and resultant heat. This is VERY bad for the engine. The effects of detonation are cumulative, meaning the damage adds up over time. Higher octane gas will be more resistant to detonation and allow your engine to run as intended.

Budman05

OK, I am a newbie. The third time I put gas in my S2K I filled 3/4 tank with regular (89) by accident. The engine has about 600 miles on it and there was 1/4 tank of 93 still in it.

Would you:
A. Add an Octane booster
B. Drive out 1/4 tank and top off each additional 1/4 tank
c. Siphon it out and dump it in my Chevy 4x4 truck

I am leaning towards B

BlitzSRM

I'd put octane booster right away... don't drive to hard too

Budman05

Thanks. I can do that. I'm so used to pumping 40 gallons of regular into my truck, I need to pay more attention

BlitzSRM

it nice filling up a car that takes a little over 10 gallons huh... and it last for a pretty long time, compared to a truck or SUV.

i think you'll have no problems, the cars will usually knock, when it's super hot out, and your straining the engine. if it's not 100+ where you live, and you drive around conservativly, you should be okay.

cthree

That octane boost isn't going to do much. There is no problem with what you did. Just run it down a half tank and put 93 or 91 in to the top. It will flush out and the engine can handle it.

BlitzSRM

So octane booster doesn't boost the octane?

Budman05

Thanks for the input. I drove it about ten miles today and had no knocking. Of course I didn't push it. I will do a 60 mile round trip tomorrow with no engine strain and top it up with the best I can find. I don't think we have a Sunoco with the real high octane in VA. Do they exist anywhere now, or is it all just BP?

I figure if I don't hear a knock or a backfire, she is running OK.

I love this car

S2kracka

You won't be able to hear most knocking unless it gets really bad. The engine has a knock sensor that will pull timing if it senses predetonation. I'd personally just drive it easy (highways miles are fine) until the tank is nearly empty and then just fill up with a quality premium. I use BP 92 personally since its the best we have in Minnesota, but Sunoco and Chevron are also excellent choices.

wwwracer

100 octane

i was sic of seeing the takata race harness post. needed to change this up.