I was going to install my rrm ecu version 2 that i just got but i have about a 1/3 of a tank of 87 octane in my car and it says that i should use 89, will it make a difference if I install it and just run 87 until im empty and then start using 89?

 

DO not do that, either run it down to nothing and put in 91 or just fill her up with 91+

if its on 87 as far as i understand you could develop nock??? correct me if im wrong..

just put in 91 and stay safe.. i run mine with shell 91 cuz it seems to have the best effect on my pigs hp.

 

so i can mix 87 and 91?

 

thats what i did.. tell you what.

just run 87 out of it (before pig) and then fill up with 91, and then install pig.

dont f around with it!