consumer reports did a study a few years ago on this, and they concluded that all brands of gas basicly performed the same, there was no noticible difference between brands of gas, i think the test was done with 87, 89, and 91 octane. I will try and find the article.
ive never even heard of aamco gas, and i have lived on both east and west coasts lol (originally from so. jersey)
out here, all aamco does is fix trannys.
regarding the consumer reports article, i have alot of respect for their findings, but from my own experience, i can feel noticeable differences most of the time. maybe its the way they process the gas here. we have that stupid clean air act that the gas co.s have to conform to specially for us in cali.
heres what i have found from my own experience....
chevron gives my car a little more oomph
mobil is often pisswater
arco is ALWAYS pisswater
costco...dont even get me started!! i know others that also say costco gas sucks. if you like engine knock...get your gas there.
texaco...never really tried
sunoco, exxon, aamco, bp ....these are not available here
just to let you know, BP, arco, amoco, thrifty, are all the same company (british petrol). exxonmobil (of course) one company, chevron, shell and texaco are same company, costco is diluted catshit. I usually fill with chevron or mobil.
mobil has always been just fine for me.
I used some cheap ass gas station the other week cause I was away from home, couldn't find a mobil, and my car actually ran like shit. It actually stalled on me a few times.
amaco or bp is overpriced crap, shell and mobil are the best two pump gases, mobil will get you a bit smoother run with less mpg and shell runs pretty good and better mpg. BP gas gets me really bad mpg