mixing different octane gas...good or bad?
 

i've gotten into the habit of putting 89 octane gas in two fillups, then on the third fillup i use 93 octane. i'm a cheap bastard and prolly not doin any good for my car, but is there any real harm in this? gas in my area has been as high as $2.80 at one point, now it's around $1.35 a gallon. let me know. thanks.

Re: mixing different octane gas...good or bad? (el_Presidente)
 

i'm sorry. i'm stupid. delete this thread please.

Re: mixing different octane gas...good or bad? (el_Presidente)
 

no harm unless you're having detination at lower octane fuels

Re: mixing different octane gas...good or bad? (el_Presidente)
 

Your octane rating is additive and proportional to percentage of each type of fuel.

E.g., 5gal of 89 + 5gal of 93 = 10 gal of 91.

Running two loads of cheap to every one of good does nothing.