|
First, OE tires are designed to the specs published by the OEM and those specs have fuel economy (rolling resistance) in mind. They can do that by sacrificing treadwear and/or grip.
Consumers don't generally care for bad wearing tires, so there will almost always be a hit in the fuel economy department when replacing OE tires.
One of the things that affect rolling resistance in tires is the amount of tread rubber - meaning that luggy tires - the ones good for gravel, mud and snow - are worse than all season tires.
Also going larger will help RR - a little bit - but those other things have a much larger effect.
So there you have it. For a heavy duty truck, you just don't have much in the way of options.
|