[slowmover]

I would say tires, inflated properly. And that is from a certified weight scale and working with pressure versus load numbers; oem vehicle manufacturer and tire manufacturer numbers range. No way I can save enough fuel to offset prematurely wearing tires due to overinflation. Handling/braking issues aren't worth overinflation risks either. This takes things the wrong direction. My compromise is about plus ten percent over indicated load pressure, for now (80-psi tires). Much depends on how the truck is being used. As DISCOUNT TIRE has a nice COATES air pressure setup in their garages these days, changing pressures as much as 20-psi in the rear is quick (plus the air dryer system works).

As to genuine vehicle modifications -- and assuming adequate highway miles -- I look forward to grille blocks/winter front plus some undercarriage covers in the next year or so.

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