I have two truck, 2006 and a 2007, both are identical except for the 2007 has an after market exhaust. I loaded the same tune in both trucks, the 2007 is getting 2 to 3 miles per gallon better while the 2006 truck lost 1 mile per gallon.
Do you think that the exhaust would make make that difference, or does anyone have any ideas on this.
Please move to the right forum.