I'm not asking if it adds HP, I'm asking what octane i should be using in my LT1? Is it ok to run the cheap stuff or should i run 91?

 

The lt1 is a high compression engine, so you should be using the highest octane you can get.

With that being said, it really depends on how picky yours is. Some people can run 87 and everything is fine, while others will run mid-grade and get some serious knock.

 

Ive been using 87 for 2 years and never had any issues. Ive tried 89 and didn't see anything different. So im good then?

 

To get the full potential of the motor you need to run premium (91 or 93 octane depending on your altitude). When you run 87 the car detects knock and starts to retard the timing, which in turn results in a loss of HP. It's your call.

 

If i ran 91 would i even feel it?

 

NO.....

 

I disagree... I can tell a difference even in my 3.8L motor... The engine runs and idles much smoother and responds much quicker. It's untelling what the difference would be in a high compression engine like the LT1

 

Wierd... My LT1 doesnt seem to like high octain? It seems to hessitate on WOT with 97?

 

And you are full of Bull Sh-t about the differences. In a v-6 it is awaste of money and in LT1 it will depend on the state of tune and if the ECM adjust to the lower octane.

 

You won't notice it as soon as you put it in, it will happen gradually as the ECU adapts to the higher octane and readjusts the timing accordingly, but it's not an instant change.

Bidicamaro: anything over regular premium fuel isn't going to get you any HP, running anything above premium on a motor that hasn't been modified to have a higher (11.5+) compression ratio or forced induction is just a waste of money.