Keeping your car healthy and running smoothly can save a lot of gas. The easiest pointer is to check your tire pressure regularly. This is a simple, cheap way to increase your fuel efficiency by around 3.3%. To find the correct tire pressure for your car, check the owner's manual or sticker in the driver's side doorjamb.
Regular tune-ups, oil changes, and smog checks might seem like an extra expense, but they will increase your gas mileage and help your engine run cleaner and pollute less.
Keeping your engine tuned is the most effective improvement, and can increase your gas mileage anywhere from 4% to 40% depending on what kind of shape it was in to start. An additional 1-2% increase in gas mileage comes from using the grade of motor oil recommended for your car.
When it's time for replacement tires, be sure to buy a low rolling resistance model. Anywhere from 5 to 15% of the fuel consumed by a typical car is used overcoming rolling resistance. Picking tires with a lower rolling resistance coefficient can help improve your car's fuel efficiency.