Knowing your compression ratio and timing will help. Altitude and jetting? Base Timing vs. total adavance? Summer vs. winter you can run low grade in the cold (burn better) and mid or high grade in the summer to prevent detonation. I now run premium in all vehicles because it is the only gas we can purchase in our area that has no ethanol. These are 351c at 11.4:1 428 cobra-jet, 289 with TRW pop-ups, 68 Jcode with 53.5 cc heads, Supercharged latemodel, or twin turbo flex. I run 91 in my 1970 250 inline maverick because no ethanol and I purchased and nos original carb for it that has 40 year old internals. You could have got some bad fuel? Just some thoughts -Scott
Must be more of a local thing then because I still see a lot of premium/E10 at the pumps traveling around WI.
I hear ya.. it's getting to be a pain to maintain consistency as some places around MN here now have 5 different choices. Non ethanol(usually 88 octane), e10, e15, e30, e85.
Im not getting in on the whole more tuning with premium gas argument because I cant say BUT HERES WHAT I KNOW TO BE TRUE. when I run 87 octane in my car it STINKS to high heaven from exhaust yes I know its not entirely the gas' fault (or maybe it is I dont know) and when I run the premium gas it doesnt smell nearly as bad the smell just about goes away. I drive the crap out of my car so its probably a tuning issue but without doing anything other than changing to premium gas something changes
