Thread: Simple question's about octane

^ sounds about right because our 1995 g20 dynoed at 131whp 100% stock w/87 octane (we always just use 87 octane --why go up when we won NASA TTF Nationals and have 12 current track records as-is?

We can go up to 150hp in TTF with the g20 BUT cannot do anything with internals without bumping to another class (so no cams, no change in trans, no cam gears, etc.) ECU tune is free but I seriously doubt we would see that much of a gain with 93 octane and a 'tune'

I'd be stunned if you gained 10whp from going to higher octane, maybe on a really really built motor.

^ realistic expectation was 3 to 4 whp with NA tune and 93 octane (not sure that was worth the price to get there so we haven't done it)

That's pretty much it. You run an octane that's high enough that it doesn't detonate prematurely. Doesn't mean there's more power in the gas, there's more power in the engine that it's running since that engine will likely have higher compression thus requiring the higher octane.

Octane is in no way, shape, or form, a measure of power. It's a measure of how much you can compress it before it goes "boom" on it's own. You're better off worrying about ethanol content.

You can gain 10whp by switching to 93 just by the different timing and tune ability. You can push the tune a little further without having to worry about knocking

Be clear though, the tune is gaining the hp, not the gas. Tons of people are looking at it backwards like that, it's what causes most of the misconceptions about octane.

Yeah by just having octane increased and no tune you wont gain anything, its all in the tune. Figured people would know that :o

Increase octane = Need more timing or you will be getting worse power/gas mileage.

How about some real numbers, our friend JP did an excellent test here:

Cool thanks for all the input so far guys........now I'm a little curious, all fuels are not created equal......have any of you guys ever noticed that you were able to wring a little more power out of your car with a particular brand of gasoline, if so what brand did you use?



Can you go into this topic a little deeper why is ethanol content so important? Give me your take on it . My understanding of ethanol is that it's a chemical they place into the fuel pretty much used as a filler to double quantity sort of like flour in cocain, is their any benefits of ethanol in fuel?



What does the abbreviation MBT mean Ben?

I only use ethanol free gas in my b13.