- tire inflation is good; proper at least, a bit above that for a 2-5 mpg bump (but never exceeding the maximum psi); you have to check this often and keep the right inflation to benefit, and you should invest in a tire gauge that gives an accurate readout too, not one of those little stick gauges
Furthermore this improves tire life significantly. However, no matter how well you maintain your tires, tires do get old.
Jeanette Isabelle