Hey guys, I'd like to change the octane I've been using from 89 to 91. Whats the easiest way to do this? I'm thinking to just get the tank on E and then fill it up with 91? Any advice would be great, thanks

 

Just start putting the 91 in. With the compression the LS1 has, you should have been running at least 91 from the start.

 

What do you mean by compression?

And what kinds of changes will I get with 91? Anything noticeable?

 

The engine's compression ratio is beyond 10:1, so its needs higher octane fuel. I think 91 is the minimum that should be used.

Just start putting 91 or 93 octane in the tank and using that.

 

Roger that, thanks

 

what does a 3.8 call for?

 

if im not mistaken 3.4 and 3.8's say go for the 89octane

 

I put 87 in my 3.4L, and 91 or sometimes 89 about every third tank in my SS -- AFAIK, if you get a knock, then you best raise the octane. I am not aware of anything detrimental apart from that condition...

 

what octane is premium gas....92??

 

Wow...dig up a long dead post...anyway...

Premium fuel ranges from 91-93 octane depending on your altitude. You should always run premium in an LS1 because it is a high compression motor. If you run lower octane the computer will start to pull timing because it will detect engine knock, and thus you'll experience a loss in power.