12 Things to Do Now to Improve Gas Mileage
The savings are based on driving 20,000 miles per year, in a car that gets 20 mpg, with gasoline priced at $3.75 a gallon.
Keep Tires at the Right Pressure
Surveys show 60-80 percent of the vehicles on the road have tires that are underinflated. That can cost hundreds annually in wasted fuel. Plus, low air pressure causes premature tire wear, and that can shorten the life of the tires. For best results, check your tire’s air pressure with a digital pressure gauge and fill to the recommended pressure shown on the decal inside the driver’s door or on the driver’s door pillar.
Replace Spark Plugs Early and Save A Lot
If your 100,000-mile spark plugs have 80,000 miles on them, they’re 80 percent worn. Misfires and incomplete combustion occur more frequently during that last 20,000 miles. You have to replace your spark plugs anyway, so do it early and pocket the savings. Even if you have to replace the plugs one extra time over the life of your car, you’ll still come out way ahead. And don’t automatically assume your plugs are good for 100,000 miles. Many four-cylinder engines require new spark plugs at either 30,000- or 60,000-mile intervals.
Replace Your Air Filter Often
Your engine sucks in 14 million gallons of air through the air filter every year. On older vehicles (pre-1999) a dirty air filter increases fuel usage by almost 10 percent. On newer vehicles, the computer is smart enough to detect the lower airflow, and it cuts back on fuel. So your engine will lack power and pick-up. Check the filter when you change your oil and replace it at least once a year, or more if you drive in dirty, dusty conditions.
Keep Your Car Aligned
If your tires are bowed out of alignment by just .017 in., it’s the equivalent of dragging your tire sideways for 102 miles for every 20,000 you drive. Here’s an easy way to check your alignment without taking your car in to the shop. Buy a tread depth gauge and measure the tread depth on both edges of each tire (rear tires too). If one side of the tire is worn more than the other, your car needs to be aligned.
Hard acceleration in stop-and-go driving costs you 20 percent in gas mileage. If you live your life in rush hour traffic and like to put the pedal to the metal, spend all your extra time at the next stoplight figuring out how you could have spent the hundreds every year you’re wasting.
An Air Dam Reduces Fuel Costs
The plastic air dam (aka “spoiler”) that’s broken or missing wasn’t just for a sporty look. If your car had an air dam, driving without it or with a damaged one can reduce your gas mileage. The air dam literally “dams off” airflow to the undercarriage of your car, forcing the air up and over the hood. That helps your car cut through the air with less drag. It also increases airflow to the A/C condenser and radiator, reducing the load on your car’s electrical system.
Replace Your Oxygen Sensor(s) Before the Light Goes on
Oxygen sensors monitor the efficiency of combustion by tracking the amount of oxygen remaining in the exhaust. But they degrade over time and that can cost you up to 15 percent in gas mileage. When they fail, the computer lights up your ‘service engine soon’ light, forcing you to incur a diagnostic fee. On pre-1996 vehicles, replace your oxygen sensor every 60,000 miles to keep your mileage at its peak. On 1996 and newer vehicles, replace the sensors every 100,000 miles. Some vehicles have as many as four, but the sensors installed behind the catalytic converter rarely fail.
Replace a Failing Thermostat
Check for Brake Drag
Keep an Eye on Warning Lights
Pay attention to your warning lights. Car owners think a glowing check engine light isn’t important because it just means you’ve got an “emissions problem.” Guess what? Emissions problems are almost always caused by an incomplete burn and that means you’re not getting the most bang for your buck. In other words, a check light means you’re wasting gas. Worse yet, all that extra gas goes right into your expensive catalytic converter, causing it to fail early. A new catalytic converter can run upwards of $1,000 to replace and then you STILL have to fix the underlying problem that turned on the check engine light in the first place. Many times the check engine light comes on due to a bum sensor or vacuum leak. Replacing a sensor or fixing a vacuum leak can save far more than what you’ll waste in reduced MPG. Stop thinking those warning lights are hieroglyphs and learn how to decipher them.