Best Gasoline for 2003 Grand Prix GT

Flatulence works well!.

What the owners manual calls for (87 regular). Its not a high compression engine so dont let anyone tell you that higher octane fuel is cleaner or will make more power in that car.

87 octane ?

Whats the decal say by the filler neck?

========= Harryface =========

1991 Pontiac Bonneville LE, 3800 V6 _~_~_~_~276,100 miles_~_~_ ~_~_

Well, premium fuel typically has less sulfur and thus decreases oil decay, improving oil life. Also, at WOT, due to pumping losses, knock conditions arise and with a higher octane fuel the engine management will be able to keep a more aggressive spark timing.

However, is premium fuel necessary? No, unless your driving style (lead-foot) calls for better transient engine response. Otherwise, it's a waste of money.

Of course, being your money, go ahead and spend it as you see fit. FWIW, many stations in my area charge only an extra 10c for premium over regular...

Agreed. It can actually can cause running problems in cooler climates... If it runs fine on 87, use 87. If you need to go to 89 (sometimes has less alcohol in some regions) do that. But usually the super is a waste of money.

He makes no mention the reason his vette needs a higher octane gas is because his vette has a higher compression. That guy didnt do any research.

ROTFL! His vette was a 79 and all L-48 (1975-1980) were ~8.5:1 compression and could use 87 octane.

Lol! I didnt even read that much of it, I just skipped to the octane=20 part.

Lol! I didnt even read that much of it, I just skipped to the octane part.

Well I should be ok then, I dont stick with one type of gasoline.

True in cold climates.

Not true for closed-loop engines.

Exactly. As I said, closed-loop engines often get most of the engine by using the most aggressive spark timing for a given condition in order to avoid ping and knock. In some of these conditions, using a higher octane gas allows the engine to use a timing for the spark that increases power slightly.

Yet, if one's main use is commuting bumper to bumper, I can't see why paying more for premium.