Tomey,Hey Norcaler I figured you would know,
Is there any difference in MPG between ATT and non-att tunes, using your timing tune?
I thought ATT might be lower due to a tighter housing when cruising at little load on the highway.
I don't prefer the ATT tune since I tow up some pretty big grades, so the data I have from my customers is all I can share. Their data has proven to me that the ATT tunes produce less mpg's when compared to the non ATT.
I hope that helps.