Fuel, Cost & Efficiency · Driver Training VideoTire Pressure & MPG

Start with the number that matters most: rolling resistance. A tire that's low on air flexes more with every rotation. That flex is friction, and friction turns fuel into heat instead of miles.

Underinflation does more than cost fuel. A soft tire runs hotter, and heat breaks down the rubber and the internal cords faster than normal driving ever would.

Overinflation isn't the fix either

Too much air wears the center of the tread faster than the edges, shrinks your contact patch, and makes for a harsher ride on the trailer and the freight.

Federal rules back this up

Under FMCSA regulations, you cannot run a tire that's flat, audibly leaking air, or worn past the tread depth minimums — 4/32 of an inch on the steer axle, 2/32 on every other axle.

Your pre-trip is where this gets caught before it becomes a problem. Walk every tire. Look for the obvious — cuts, bulges, uneven wear, anything embedded in the tread. Then check pressure with a real gauge, cold, not a thump with your boot.

Your company standard: check tire pressure on every pre-trip, cold, with a calibrated gauge — never a visual guess. Match pressure to the load and inflation chart for your tires.

Do this right and you get two things at once: fewer roadside surprises, and real, measurable fuel savings across a year of loads. That's not a tradeoff. Proper inflation is one of the cheapest ways to protect your safety record and your fuel numbers on the same tank of diesel.