Because tire pressure changes with temperature, you should check and adjust pressure when the tire is cold and when the vehicle has been sitting for at least three hours. Vehicles burn more gas and emit far more pollutants in their first few minutes of operation because the emission control systems have not warmed up and reached peak efficiency. When possible, carpool, ride mass transit, walk, or bike to your destination. Drag reduces fuel efficiency. If you sometimes need to transport large items, use a removable rack, or if possible, carry the items in the trunk or inside the vehicle.
Heavy loads increase drag.
Remove heavy items from the vehicle when you don't need to carry them. A clean car body can reduce drag by up to 12 percent thereby improving fuel economy. Stop when the pump automatically shuts off. If you continue to refuel after the pump has shut off, you increase the chance that you will spill gas and release harmful gasoline vapors into the air. Replace the gas cap tightly.