Under the mileage crunch the OEM's are under now, if there was any mileage benefit to be had with a tonneau cover, all of them would come factory equipped, especially the EcoDiesel; if it made a difference it would have one stock and get 30...
If you just like the looks, get the lower-cost soft cover. If you're after keeping things locked up, get the hard cover.
If you just like the looks, get the lower-cost soft cover. If you're after keeping things locked up, get the hard cover.