I recently bought a 99 f150 2wd 4.2l. Big change from my f250 ccsb v10! Anyway, I've been doing some maintenance and getting familiar with the truck. Installed my scanguage but I'm having some difficulty with the AVG reading for fuel economy. I installed my 235/85/16 winter tires from the Super Duty, replacing the 235/70/16 stockers, and now I think my mileage computations on the scanguage are way out of wack.

Does the scanguage use the digital odometer reading to calculate fuel economy? Can I recalibrate my odo for the taller tires? Thanks.