With my street tune I run 85 octane and with my performance tune I usually run E85.

 

Where the hell do you even get 85 octane? That's like the garbage they put in golf carts.

 

I use 87, and with the mods I have done and the 3815 on performance tune I have no pinging.

 

I use whatever my neighbors use.

 

LOL! Good one.

 

Yeah what the other guys said about the plenum gasket sounds right... its notorious for developing leaks on those dodges, and you shouldn't have any problems with 87.

 

In high altitudes, the octane level can be lower. Our regular is 85 octane, mid grade is usually 87, sometime 89, and premium is usually 91 octane.

 

Really? I learn something new everyday...

Is it less expensive? How does that work with programmers?
I assume because the air is thinner that the engine draws less into the cylinder... so there would be less compression in each cylinder, which would deter knocking?

How does that effect overall power?

Sorry for all the questions. I just never even thought about it before.

 

I use 89 because I need to replace my plenum gasket.

 

I used 87. I figure with all the mods I'll have to run something higher