bill4777

do gas grades really matter?i have a 3.5v6 engine in a 2007 buick rendevous i put 89 gas grade in all the time butwith gas prices being out of control does it really matter what grade i put in???

mdcbert

Two things you should know about gas...High octane gas is only for high compression engines, Your car does not have very high compression, you dont need it!! Higher octane actually resists exploding, so it doesn't preignite and cause pinging.interesting read on this here...http://www.bajajusa.com/High%20Octane.htmONLY use Shell, Texaco, or Chevron (you only need regular) because these are the top 3 of the tip tier gas brands. They all have the detergents in all grades to keep your valves clean, even in regular.interesting read on that here also...(click "retailers" at the bottom for a list of all the top tier brands..http://www.toptiergas.com/

Adam9276

Unless your vehicle requires a higher octane gas (It would say something like Premium Fuel Required), there is really no advantage to using anything higher than 87 Octane. In most cases, using a higher octane than recommended, will result in a decrease in gas mileage.It should tell you what the minimum octane rating of your vehicle is in your owner's manual.EDIT: I like how mdcbert edits all of his answers after his initial post, just so that he can be the first answer. His original answer: http://img406.imageshack.us/my.php?image=mdcbertno3.jpg

ohlaura

I don't think with the newer models it does. With higher mileage cars it's best NOT to use the cheap stuff. I think Chevron is the best gas, especially for high miles!EDIT: AAHHH! So that's how they do it Adam ... VICIOUS!!

IanF9272

Use what your owner's manual says to use. Using higher than that in an engine with no problems will NEVER help, nor will it hurt anything but your wallet. EVER. Using lower than that will NEVER help, and at worst could damage your engine. Using the SEARCH FEATURE and thus not asking a question that gets asked here twice a day will NEVER hurt, and will ALWAYS help.

kevint6043

My understanding: There only a few refineries left. Shell/Chevron/'Joes' all get their gas from the same refinery. Maybe they put additives in after they get it, but it's the same juice. The octane ratings are certified so therein lies the difference.My experience: I normally drive a Toyota with electronic fuel injection (efi). I can hear a lot more pinging with 87 than 91 at first (idle to movimg), then it goes away. I have driven cross country (NY - LA/SF) frequently and have been able to get 93-94-95 octane gas. Those higher octane gases gave a definite & measurably higher MPG (better fuel economy) with an efi equipped engine, but made no difference on a carburated engine except a high compression engine.