[zeromotorsports]

octane is just a resistance to burn....the higher the octane number the less likely it is to detonate. unless you have excessive spark advance, high compression, n20 or boost higher octane fuel does nothing for you

 

[zeromotorsports]

QUOTE

i dont get it then. ive been hearing stuff about how 91 premium can hurt the car. i've always thought the higher octane the better because you have less chances of early detenation. yes, running higher octane fuel might not do anything for the car performance or mileage wise, but you have a lower risk of early detenation. you go to any manufacturers website and they always have the recommended fuel for the car OR higher. recommended gasoline for the tC is 87 octane OR higher. same goes for cars that are 91 premium recommended. so how will higher octane fuel be bad for the engine when the manufacturer says its ok?[/b]

while unnecessary, higher octane will NOT hurt your car or your performance

 

[zeromotorsports]

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Ford says using anything greater than 87 octane in their standard trucks will void the warranty. I don't know why this is, but that's what they say. Toyco doesn't say this.[/b]

ive never heard that before...thats pretty messed up

QUOTE

I have seen guys dyno with extremely high octane fuels when they didn't need it (117 when 105 or 107 would have been fine) and actually lose power, but I doubt there is any difference in performance between unleaded pump fuels.[/b]

i could see how it could cause ignition problems when using extemely high octane when not needed but not with pump gas