91+

 

Shell V-power has additives in their gasoline as well as octane. So it will help your engine even if you dont need it. but it wont add any power.

 

Increased ocatane will NOT get you more power in adn of itself. You can run a higher octane and advance the timing (the ecu will do this to a point) and get more power, but only a little and only to a certain point. THe LS1 has two knock sensors, if you run a lower octane and the engine detonates the ECU will pull timing and the engine will run fine (although a bit down on power). There is absoulutly no reason to run anything more 93 in our cars.

 

i run 91 most of the time unless I am going to spray, that is the only time i really search out 93, or I will use 92 and an octane booster. Not sure about the validity of octane boosters, if they actually increase the rating or not tho