Hi, Sorry if this topic has been used to death before... but I would like to know if X drivers see any significant difference in power/economy when using low octane fuel vs high. I think the book says 87 for a 2004 SE... I have always believed in high octane - I ride a bike which struggles on low octane.

Can any type of tuning/chip be done to maximise the performance vs octane of fuel used? - one for the tech heads~!

Mine is a new (to me) car and I'm on my 4th tank of gas so can't make any empirical measurement yet.

Cheers
Steve