MR.Mustang

I have a SCT X-cal II and a JLT II form Evoloution. I have three preloaded tunes 87, 91 & 93. My car has never been on a dyno. I was wondering how much horsepower there is between each tune. Has anyone dyno-ed their car to find the horsepower diffrence between a caned 87 octane and a 93 or other octane tune?

androdz

What changes is the timing on the tunes. You can run 87 octane on a 93 octane tune but ur car will misfire and even piston a tad. Not recommended.

MR.Mustang

I understand the timing changes and all of that but my question is how much horsepower difference is there really between say a 87 tune and a 93 tune on the same car? I was just wondering if anyone here had their canned tunes dynoed for each octane level?

chirostang

I have exactly the same setup and was wondering the same thing. I loaded the 87 first and ran that for a couple of tanks. I then changed to the 93. I can honestly tell you that I can't feel the difference. The only thing that I notice is that my mpg went from 17 to 15.4. Ouch.