fuel question, regular fuel against hi-octane fuel Options

[junkmate]

well... ive been driving my SS-III (which i assume has the 3S-GE engine) for over a year and a half now, and only recently did i realise that the petrol cap says "ONLY HI-OCTANE FUEL"... and ive been using regular the entire time...

is that like... really bad?
is it worth changing to hi-oc from now on?

(ps. when i first got the car my japanese wasnt so good, so it took me a while to actually be able to read that warning so im only half a retard...)

[junkmate]

I see your point. I guess ill start using hi-octane (theres only three types of fuel in most gas stations around here, diesel, regular and hi-octane) since its only an extra 10cents a litre.

As for whether the hi-oc is 94 or 96, i have no idea, and i would hope that all gas stations around my area use the same type, since i guess mixing them wouldnt be too good? Its all pretty confusing since i am pretty much a newbie driving a celica cos i "loved the design".

Dare i embarrass myself even more and ask what the hell 'knock' is?!
i'll go read up on the forums

thanks for all your help though, you're a patient lot even with newbies like myself