Can the type of gas I put in my 2004 Monte Carlo LS affect the performance of my 3.4? For example, would I get more power if I put in 93 octane (super premium, I believe) instead of the normal 87 octane (regular unleaded)? Would it make a difference, especially since I have the new K&N air filter? Thanks.

 

From what I've read using higher octane gas can do more harm than good, at least in engines that are designed to run on the lower octane. I have never read or heard of any benefits running 93 octane opposed to 87 octane.

 

ok, here's a quote from another forum:

Basically the higher the rating the higher the flashpoint is. High octane is used in high compression or forced enduction engines to reduce pre detonation which is where the fuel combusts before the spark is causing high cylinder pressure which can be bad. If your car doesn't suffer from detonation then you are wasting you money on high octane it does burn with anymore power or burn cleaner or any of that mumbo jumbo.

 

Yep, it can make a difference. But not in the way your example is asking. But before MonteJass chimes in with his Hypertech response they claim a 20hp gain with premium gas using the programmer. But w/o use of a programmer, the only benefit you'll get is weight reduction...............by lightening your wallet.