Use the Manufacturer Recommended Oil
If you use a heavier oil than your car's motor is designed for, it could cut into your fuel efficiency by as much as 1-2% (fueleconomy.gov).
Keep Your Tires Properly Inflated
Under-inflated tires are a major mileage killer. Check your tire pressure every few weeks (and before all major trips) to ensure you're making the most of each fill up.
Fuel Savings: Up to 3% (fueleconomy.gov)
Check Your Alignment
A vehicle that's out of alignment has more rolling resistance, and therefore uses more fuel to get down the road. About.com's Guide to Auto Repair recommends having your vehicle's alignment checked once a year (sooner, if you notice pulling, uneven tire wear or an off-centered steering wheel).
Get a Tune Up
Pull that owner's manual out of the glove box to see what regular maintenance is recommended for your car; then, follow the recommendations to a tee.
Fuel Savings: 4% on average, but could be much more (fueleconomy.gov)
Replace Your Oxygen Sensors
Oxygen sensors help your car's engine to run as efficiently as possible, but they wear out over time. In vehicles manufactured from the late 1970s to the early 1990s, they should be replaced every 30,000 miles. In vehicles manufactured after the mid-1990s, they should be replaced every 100,000 miles.
Check Your Gas Cap
A broken or missing gas cap makes it easy for gas to evaporate from your tank. Inspect your cap, and get a replacement, if needed.
Fuel Savings: 1-2% (Plant Green)
Pick Your Tires Carefully
Running oversized tires, wide-profile tires, tires with off-road tread, or high-performance tires on your vehicle will reduce your fuel efficiency. If you aren't sure what size tires are recommended for your car, check the owner's manual.
Clean Out Your Car
Extra junk in your trunk (or cabin area) is extra weight that you're paying to haul around, so get rid of it.
Fuel Savings: Up to 2% for every 100 pounds removed (fueleconomy.gov)
- A recent study shows that changing the air filter in a vehicle with a computer-control, gasoline engine and fuel injection does not improve fuel efficiency only performance.
- Only tackle the jobs that you know how to do. Refer to a mechanic for the rest.
- Always take the proper safety precautions when tackling a car repair on your own.
What You Need
- Your Vehicle Owner's Manual
- A Tire Gauge