any problems with running a tank of 100 octane throught my '86 na? Finally found a place that sells it around here.

Thanks

 

Well, first off, why would you want to? It's not going to yeild any performace increase or anything like so, and might increase your chances of detonating.

 

Ummm...

I thought that a higher octane gas fought off detonation. I know that there really isn't any performance increase, but having detonation MORE likely? WTF?

 

Don't waste your money. Run 87.

 

I've been runnin 87 in my tank for about 3 yrs solid. I mistakenly put it 93 two weeks ago and it seemed to run a little better. I might try it for science sake, wait til i'm low on gas, and buy 3-4 gallons of 100. I'll let you guys know.

 

100 octane-- leaded or unleaded?
Don't waste your money. It won't do anything for you unless you have SC/turbo/N20/seriously advanced timing.

Here big brothers comment:
http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

Heres a pretty simple explanation:
http://theserviceadvisor.com/octane.htm

I tend to run 89 during the summer and 87 all winter and my timing is advanced a couple degrees. I have no problems.
Stick with name brand gasoline that has lots of business. Fresh fuel is just as important as octane.

My owners manual recommends 87 or higher.
My engine has 100k miles with typical rotary carbon buildup. I sometimes wonder if the carbon buildiup will artificially increase the compression ratio. This may be one reason why some car seem to run better with a little more octane.
Big oil thief Shell mentions this
http://www.shellus.com/products/prod...roperties.html

 

I put 91 in my car by accident once, and it seemed to run a bit worse. The car still drove fine, but the idle was a little weird.

 

100 octane is going to be race gas of some type, which will yield more power if the engine is tuned for it.

As for pump gas, your 86 NA is rated for 87 octane (R+M / 2). If it knocks on 87 even after a full tune-up, then use a different brand of gas or move up to 89 octane. If it doesn't knock, then the higher octane pump gas is just a waste of money because all grades of unleaded pump gas have basically the same power per pound. Race gas has more power per pound, but you need to know its composition to estimate its power level, or you need to ask the supplier how many BTU's per pound. The octane rating is still just an anti-knock rating, even for race gas.

 

Sonicrat...Higher octance = burn slower = burn cooler = less chance of knock. Learn that


As for race gas in a regular car, if all things are the same, youll probably run worse. Also, DO NOT run leaded race gas through your car if you have cats.

Leaded gas also ruins O2 sensors over time. Heated O2 sensors will last a little longer...but they still get messed up.