My truck has unfortunately had periods when I was unable to use it. (Multiple Sclerosis can do that.) Anyrate, although the truck seemed to drive ok and had plenty of power... even towed the trailer considerable distances... the mpg has been falling off serously. This has gone on for a couple of years and the truck has been through numerous state inspections, various mechanics & dealership. (The dealership said "no codes, nothing to fix!") The answer was found by accident at the most recent state inspection (a different mechanic) checked the front end and found the wheels would barely turn. The cause was two fold... the brake pads themselves were delaminating (although there was suffient material visible). Also the diameter of the disc had rust expanded so that it brushed the frame which supports the calipers. Any rate, a brake job brought the mpg back to the original mpg. The interesting thing is that the powerful CTD drove pretty normally with the brakes like that... although it is peppy and FUN to drive now!Russ

It doesn't take much of a "drag" on the brakes to knock the mileage down!!! Imagine riding your bike with just a little bit of brake pressure applied!!! Need I say more. I thing many of the "poor mileage" claims may be due to this!!! These engines put out so much power and are so well cooled that a little bit of brake pressure isn't even noticable to the cooling system!!!

huh, woulda never thought of that....my truck gets good mileage and the brakes work good though...hmmm....

That is interesting Russ... I had a similar problem with the rear but it was caused from debris being wedged between the piston and the caliper and pinning the piston against the rotor... Simple caliper rebuild and washing did the trick and cost me less than $30 bucks for the 2 rears to be done...