Odometer question

[Chamberpains]

5280' = 1 mile
5280'/518 rpm = approx.10.1931' distance traveled per revolution
5280'/508 rpm = approx. 10.3937' distance traveled per revolution
Or a difference of approx. .2006' or 2.4072"
Which comes out to approx 103.9366' difference every mile the ECM mistakenly counted.

508 rpm tire is larger than the 518 rpm tire.

So say the ECM has been wrong since mile 1 and its now counted 406,000 miles than the equation would be
406,000 miles x 103.9366 unrecorded feet per mile = 42,198,259.6 feet or approx 7992 miles not accurately recorded.

Now all that math I just showed means absolutely nothing towards what this guy's complaint is unless he actually knew he was losing about 104 feet per recorded mile compared to true traveled mile and cared. This just simply shows that he may not have charged for or reported 7992 miles in the life of the truck. My post is just a collosal waste of time.

Your welcome.

As far as why your odometer is off from the ECM... could be some one changed the instrument cluster or your truck had a brain fart or a bunch of reasons. My odometer once lost about 50,000 miles being towed 350 miles into Denver Colorado. I don't know why.... I usually go with Gremlins. You fed one after dark and thats all. Don't do it again and offset the mileage using Insite to correct your speedo head if it will allow it to change. If not, correct your tire size so your mph (mile per hour) is accurate. And roll on down the road knowing its recording more accurately now.