When to change octane if changing tune?

[ecko51]

What is the proper way to go up or down in octane as far as fueling and when to change the tune?


Thanks, Mike

 

[bigcat]

you want the tank as low as possible before filling up and changing the tune.

 

[Saleen-wana-be]

yeah, fill up then tune, never tune then fill. Although if your going down from like 91 to 87 it wont really matter, but when going up, run it almost to E, fill up then tune.