Motors with higher compression mean that their combustion process is of a higher pressure. You need a higher octane gas because the increased octane will not allow the gas to prematurely combust at these higher pressures like fuels of a lower octane would.

Today's gasoline is very low in octane compared to 30 years ago where they were pushing into the 100's, I believe. Back then, compression ratios into the 11's and 12's were possible in street engines with pump gas. These days, those same high compression motors would prematurely ignite/detonate with modern low-octane fuels.

GM calls for a MINIMUM of 91 octane because the LT's and LS-engines walk a tightrope of streetable, relatively high compression which is 10:1, or something like that. Anyone who runs ANYTHING BELOW 91 OCTANE is not only depriving their car of power, but running the risk of pre-ignition/detonation and ruining their motor.

In summary: 1. LT and LS engines are high octane/pressure engines that need higher octane gas, or else. 2. Only idiots run with lower gas. 3. Biel is way hotter than Alba...

 

so ur saying the highest paid gas is the best for a 91 firebird/formula?

 

another thread revival.......not nessessarily the 'highest cost' gas, but the highest octane. which, of course, happens to be the most expensive. that doesnt mean you should go to a station thats .05 more exp. then the one across the street, since you think itll have better quality gas. just use the cheapest, NAME brand gas you could find. name brand meaning stay away from shaddy 'bill's gas' on the corner. when regular was up around $3/gallon here, i tried a cheapo gas station for a while, saving almost .10 per gallon. i got, no exaggeration, 50 MILES less per tank in my 05 colorado, then using other brand gas, during the SAME distance/driving style.

all gas is nearly the same. no matter what ANYONE tells you, dont forget there are only, and i mean only, 6-7 oil companies in the world. which means every single gas station in the US gets their gas from one of those companies. the only differance is how the individual station sells the gas.....from the bottom, top, how old/new is the tank, etc. he could very well add water to the tank just to get more out of it. its been done.

 

 

Your freind is an idiot. The car will run like **** without the premium.

 

use 93, and it does matter. I tuned my car on BP 93, and now, if I just go into handi mart and snag some 91, i get KR believe it or not. 93 or better only for my car.....

 

Of course it matters for a performance engine. It would be a total waste to put premium gas in a basic 6 cylinder engine like your mom's minivan. That is an example of throwing away your money, but not for your LS1. Since 1996 I've used BP (Amoco) premium in my Formula and current T/A with ZERO problems whatsoever. Cost is NOT a factor for me either when it comes to fuel as it amounts to ZIP in the long scheme of things.