Quote Originally Posted by Kennedy View Post
Are you running the low tune?

Have you verified speedo with a GPS?

The low tune should leave the DIC just as accurate as it ever was.
Yep, running low tune - assuming I have it right, Low is switched away from the notch on the switch?

I checked the odometer via mile-markers on the interstate - two different straight (Indiana) stretches of 10 miles and it was less than 0.1 miles off. Next time I have my GPS with me in the truck on the interstate, I'll check it that way too.

I will be filling up again this weekend probably of at least 1/2 a tank so I'll see how that goes as it will be without a trailer. The error on a partial tank was 3.4% and the error on two full tanks pulling a trailer was 7.8% and 5.3%, The 7.8% was out of town but the other two were normal place, pump, and filled into the neck.