What will 100 octane gas do?

[conradtan]

Forgive me for my ignorance, but I found a gas station selling 100 octane gas (at $5.50 a gallon) I believe primarily used for boats. It is by a lake. My question is, what would happen if I put a tank of that stuff in my car? Just curious more than anything.

[drsmith]

Personally i would've thought the ECU would adjust the timing to a degree to compensate, just as it would if it were poor quality, thus 'buffering' the potential benefits. The car would have to have a specific 'map' to run on such a high octane fuel from my experience so without it, it would be a waste of money.

[cas951]

The ECU will adjust and provide better throttle response and a slight hp gain. Specially with California having only 91 Octane where other states have 93 to 95 octane available. I wouldn't use a tankful of 100 octane but a mixture of 91 and 100 octane to come up with a 93-94 octane mixture. Since you're in Sj you can go to a 76 station located at Almaden Expressway and foxworthy. They have 100 octane available at the pump unleaded.

[conradtan]

Ah... ok. Someone told me it would be bad since the engine will be running hotter than usual. Yet another person told me higher ocatne = faster car haha!

[eightsandaces]

I have used 104+ and several other boosters, most of which I think were toluene based. The biggest difference I notice is how smooth the engine runs and perhaps a smidgen more power, it's worth 6 beans to find out. Beware though, use a funnel, that **************** will eat clear coat like piranha on a chicken leg.

[Viper5]

I believe it would not do anything bad to your car. Higher grade of fuel is always better. If however you go to lower grade, detonation and preignition may occur. I am not a mechanic so take this lightly.

[Adam]

I belive Edvelin dyno'd his car with 100 oct race gas and it netted him about 3 hp.

[941MXVET]

Originally Posted by conradtan

Ah... ok. Someone told me it would be bad since the engine will be running hotter than usual. Yet another person told me higher ocatne = faster car haha!

Although its not exactly the same, a friend and I tested our 4 stroke 450cc MX bikes with an infrared thermometer. The bikes ran about 12.5 to 1 compression so they were somewhat close to our cars. We read the temp at the exhaust port, and found 110 race gas to run 15 degrees cooler then the 91 pump gas.