Keep tires inflated at the recommended pressure listed in your vehicle owner manual. Start and stop your vehicle slowly when possible and decelerate before corners. Fast stops and starts and tire squealing wear more rubber off your tires and take miles off their operating life. Drive the speed limit. Higher speeds increase tire temperature and cause extra wear.
Radial tires improve gas mileage.
Steel-belted tires are generally the most efficient. Slow down on rough roads and avoid potholes. Damage to your tires will decrease their useful life. Finally, consider buying retread tires to encourage markets that reuse old tires. Tires which are improperly disposed are an unsightly public nuisance.