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Improve Fuel Economy & Spend Less on Gas

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Improve Fuel Economy & Spend Less on Gas

This guide explains practical ways to improve your vehicle’s fuel economy, helping you spend less on gas. You’ll learn driving habits, maintenance routines, and planning strategies that can increase miles per gallon (MPG) or liters per 100 kilometers (L/100km). No special tools are needed—just a willingness to adjust how you drive and maintain your car.

What You’ll Need

  • Your vehicle’s owner’s manual (for recommended tire pressure and maintenance schedules)
  • A tire pressure gauge (or use the one at a gas station)
  • An air pump (available at most gas stations)
  • A notepad or phone app to track fuel consumption

Step-by-Step

  1. Check tire pressure monthly. Under-inflated tires increase rolling resistance, making the engine work harder. Use the recommended PSI (pounds per square inch) listed in your owner’s manual or on the driver’s side door jamb sticker. Check when tires are cold (before driving) for an accurate reading. Add air if needed.
  2. Remove excess weight. Clear out heavy items from your trunk or back seat that you don’t need daily. An extra 100 pounds can reduce fuel economy by about 1%. Remove roof racks or cargo carriers when not in use—they create aerodynamic drag, especially at highway speeds.
  3. Drive smoothly. Accelerate gently and brake gradually. Avoid rapid starts and hard stops, which waste fuel. Use cruise control on highways to maintain a steady speed, but avoid using it on hilly terrain where it may downshift unnecessarily.
  4. Observe speed limits. Fuel economy drops sharply above 50 mph (80 km/h). For every 5 mph (8 km/h) over 50, you pay about 7% more per gallon. Slowing down from 70 to 60 mph can improve MPG by up to 15%.
  5. Avoid idling. Turn off the engine if you’ll be stopped for more than a minute (except in traffic). Idling gets 0 miles per gallon. Modern engines don’t need a long warm-up; start the car and drive gently after 30 seconds.
  6. Plan your trips. Combine errands into one trip rather than several short ones. A warm engine is more efficient than a cold one. Use navigation apps to find the most direct route and avoid traffic congestion.
  7. Use the recommended motor oil. Check your owner’s manual for the correct viscosity grade (e.g., 5W-30). Using the wrong oil can increase friction and reduce efficiency. Change oil according to the maintenance schedule.
  8. Keep your engine tuned. Replace spark plugs, air filters, and fuel filters as recommended by the manufacturer. A faulty oxygen sensor or dirty air filter can reduce fuel economy by up to 20%.
  9. Use the right fuel. Use the octane rating recommended in your manual. Using premium in a car that takes regular doesn’t improve economy and costs more. Don’t overfill the tank; stop when the nozzle clicks once.
  10. Consider fuel-saving technologies. If you’re in the market for a new car, look for models with start-stop systems, hybrid powertrains, or cylinder deactivation. These can significantly reduce fuel consumption in city driving.
  11. Track your consumption. Record your mileage each time you fill up. Divide miles driven by gallons used (or liters per 100 km). This helps you notice if something changes, indicating a maintenance issue.

Common Mistakes

  • Ignoring tire pressure: Many drivers forget to check until the tire looks low, but even a few PSI under can hurt economy.
  • Using premium fuel unnecessarily: If your car doesn’t require it, you’re wasting money.
  • Idling to warm up: Modern engines don’t need long warm-ups; idling wastes fuel and increases emissions.
  • Carrying unnecessary roof racks: Even an empty rack creates drag, reducing highway MPG by up to 5%.
  • Aggressive driving: Rapid acceleration and hard braking can lower fuel economy by 15-30% at highway speeds.
  • Skipping maintenance: A clogged air filter or worn spark plugs can significantly reduce efficiency.

Tips

  • Use the “eco” mode if your car has one—it adjusts throttle response and transmission shift points for efficiency.
  • Keep windows closed at highway speeds; open windows increase drag. Use the ventilation system instead.
  • When driving in stop-and-go traffic, maintain a steady pace and try to “time” green lights to avoid stopping.
  • If you have a manual transmission, shift up early (around 2,000-2,500 rpm) to keep engine speed low.
  • Consider carpooling or using public transit occasionally to reduce your overall fuel usage.

Troubleshooting

If you notice a sudden drop in fuel economy:

  • Check tire pressure immediately—low tires are a common cause.
  • Check the check-engine light. If it’s on, have the codes read at an auto parts store; a faulty oxygen sensor or mass airflow sensor can cause poor economy.
  • Inspect the air filter; if it’s visibly dirty, replace it.
  • Make sure you’re not carrying extra weight (like heavy tools or sports equipment).
  • If the problem persists, have a mechanic perform a tune-up, including spark plugs and fuel system inspection.

If you’re not seeing improvement after following the steps:

  • Give it time—some changes, like new tires or a tune-up, take a few tanks to show results.
  • Track your consumption over several fill-ups to get an accurate average; short trips can skew data.
  • Consider that your driving conditions may have changed (e.g., more city driving, winter weather).

Frequently Asked Questions

Does using cruise control really save fuel?

Yes, on flat highways, cruise control maintains a constant speed, which is more efficient than a human foot that tends to fluctuate. However, on hilly terrain, it may downshift aggressively, so it’s better to use it on gentle grades.

How much does a dirty air filter affect fuel economy?

A severely clogged air filter can reduce fuel economy by up to 10%, but modern engines have sensors that adjust the fuel mixture, so the effect may be smaller. Still, replacing a dirty filter is cheap and helps.

Is it better to use the A/C or roll down windows on the highway?

At highway speeds, open windows create significant aerodynamic drag, so using the A/C is usually more fuel-efficient. At low speeds around town, rolling down windows is better because the A/C compressor adds load.

Can fuel additives improve gas mileage?

Most fuel additives don’t provide a measurable improvement in fuel economy. The best way to improve economy is through proper maintenance and driving habits. Avoid spending money on “miracle” additives.

Does driving with the bed down on a pickup truck help?

For pickup trucks, lowering the tailgate can reduce drag, but the effect is small. Using a tonneau cover can also help. However, the best improvement comes from not carrying unnecessary cargo.

How often should I check my tire pressure?

At least once a month and before long trips. Tire pressure naturally decreases over time, and temperature changes affect it—about 1 PSI drop for every 10°F (5.5°C) drop in temperature.

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