The dealer said the 07 6.7 would not go up to a 35 tire size. I tried the SC Cortex and it still adjust my speedometer. Does this throw my mileage off. I'am normally show about 12 to 14 mpg. Any answers.
This is exactly what I do, just add 10% to whatever the odometer says to get actual mileage.I add 10 miles for every 100 miles i drive so if my trip meter says 350 i add 35=383/# of gls of fuel added at fill up and there you have it....i got this # by zeroing out the the trip meter and my gps then drove till trip said 100 miles and gps then said 110miles:CRY: