[slowmover]

. . Air up the tires

OP, there is some work to be done here (reading for knowledge).

For pickups/suvs the tire pressure is critical to best handling & braking which trumps the very slight mpg change.

1] Pressure according to load

- It may be that your load is standardized, pretty much the same from trip to trip. I highly recommend you incorporate a stop at a certified public scale, such as the national chain, CAT Scale (online locator available) on your way out of town, with full fuel, all persons, critters and gear aboard.

2] Remain within factory guidelines

- The second reason for factory sizing of tires is to work within a very carefully established balance of factors. Remember the Ford Explorer fiasco? Since then the factory engineers have doubled down (or been listened to) in re tire specifications.

There is

A] An upper and lower set pressure limit
B] There is a FF/RR bias

Both of these are to be maintained. A scale ticket gives a per axle wheel position average (front axle, rear axle and total). One can "see" where one is. The minimum amount of pressure to support that load is very possibly below what the factory sets as a minimum. The maximum is lower than the sidewall marking. Stay within the limits, A & B.

But one can move up a few pounds (3-5 psi) if within the range, and likely not do much to upset the vehicle prematurely. The test (according to EM contributor and tire engineer CapriRacer) is that

after 1.5-hrs steady-state driving, the pressure rise should be no more than 3-5 psi.

The trick to all this is to find that best "lowest" psi number, and then adjust just barely upwards. Or, not. "Reading" tires with an infrared thermometer is what some of us do (pro drivers and RV'ers) to keep an eye on things; and we adjust according to season or condition as well.

Steering control, body roll, and braking are all predicated on tires being able to absorb a certain amount of road irregularities while maintaining a set course without steering corrections. Tires that are too "hard" cause a high COG vehicle like a pickup to lose traction or tire/road contact too soon.

Once you know the likely weights, and season-to-season changes, the range of pressure adjustments is quite small (the reason for records and scale tickets).

Frankly, long tire life trumps a few mpg. Best tires, and best EM practices for high mpg will mean long tire life. It is no mistake that on my pickup that it got 120k on the first set of tires before they were worn out from either time or miles . . . and I may not have to buy the second replacement set until the truck has a quarter-million miles on it.

Fuel economy is just a sub-set of ECONOMY where all dollars matter.

A set of CENTAMATIC wheel balancers (Alvarado, TX) and tires/rims done on a HUNTER GSP-9700 -- plus a TPMS system -- are all just good additions to keeping up with an expensive set of tires, and to the promulgation of best practice in keeping things in top shape.

In the same vein: polyurethane anti-roll bar bushing replacements and KONI shock absorbers (if available, if not, then BILSTEIN).

Best practice in going down the highway is not only near zero steering inputs, but to not have to change lanes, either. The smart speed (based on road, load, traffic, weather, driver condition, etc) is what one learns as skill improvement is taken seriously. Best mpg is just a part of that (at a generally, but only slightly, lower speed).

The vehicle that needs the least amount of corrections to remain lane-centered under all conditions will win any mpg contest over an otherwise identical vehicle (where driver skill is hypothetically the same).

So, from both the longest life and mpg perspective: do what is necessary to preserve tread life (past pressure). This means respecting exit ramp and flyover (overpass) limits for example. This is not a car. If it sez 30-mph, then drop it down to within 10-mph of that under perfect conditions and do that before you get there as using the brakes is an EM no-no. Keep perfectly centered in the lane, any lane you're ever in, under any and all conditions. No cutting the corner. Same for intersections as the law states that all turns must occur only within the intersection itself; one must enter the new lane of travel already in a straight line. (Re-reading the Texas Drivers Handbook is good EM practice).

Finally, anyone getting less than 70k out of a top set of tires needs remedial driver training (the vast majority of folks out there). Include ones self in this assessment of need.

It all pays, directly (mpg) and indirectly (tire life).

.