Jeez, I keep thinking of all the little, inexpensive things I do to boost my gas mileage.
Keep your tires fully inflated. We keep all our tires at the max molded into the tire sidewalls. Under-inflated tires create more rolling resistance, contributing to lower fuel economy. Under-inflation also causes less 'road grip' and reduces brake efficiency. (We also find fully inflated tires provide better traction on ice and hard-packed snow.)
Under- and over-inflation is also expensive, causing excess tire wear. Significant wear down the center of the tread indicates over-inflation and the same along the outsides of the tread (even on both sides) indicates under-inflation.
I even made a shop take my daughter's pick-up back into the shop to re-inflate the tires. They had lowered pressure in the front tires to match vehicle specifications, although they were only supposed to do an oil and filter change. They didn't have any room to argue because I'd written,"Keep tires inflated to max pressure molded in tire sidewalls," on the job ticket. (I've had problems in the past with shops reducing inflation without my approval.)
