Virginia Auto Service

Getting the Best Gas Mileage Out of Your Vehicle

Currently gas prices in Phoenix are down $0.70 from where they were at the same time last year. Phoenix residents are all breathing a sigh of relief and loving the extra cash in their pockets. But, what if we told you that there are things that you can do to save a little bit more at the pump? There is nothing we can do about the cost of gas, and we can’t all run out and purchase a new more fuel efficient car, but we can keep our cars in shape and drive more proficiently to help reduce the amount of gas we use.

Getting the Best Gas Mileage Out of Your Vehicle

Follow these tips to get the best gas mileage out of your vehicle:


Drive More Efficiently

Follow the Speed Limit– Not only does following the speed limit keep you safe, but it saves you money. Gas mileage quickly decreases at speeds above 50 mph. According to every five miles per hour you drive over 50 mph is like paying an additional $0.12 per gallon of gas.

Don’t Haul Cargo on Your Roof– Aerodynamic drag, or wind resistance, is increased when you haul cargo on your roof thus lowering the fuel economy. A large roof-top cargo box reduces your gas mileage anywhere from two to 25 percent, depending on the speed in which you are traveling. (The faster you go; the more gas mileage you lose.) Try using a rear-mount cargo box or tray instead as they only affect gas mileage by one to five percent. Also, remember to remove any external cargo container when it is not in use to save gas and money.

Use Cruise Control– When you use cruise control you are not continuously hitting the gas pedal and are keeping a steady speed, which in turn saves on gas.

Stop Idling– According to, idling can use a quarter to a half gallon of fuel per hour, depending on engine size and air conditioner (AC) use. It is best to shut your engine off whenever your vehicle is parked. Re-starting your vehicle only uses about 10 seconds of fuel, which is much less than the five to ten minutes or more that you use while letting your vehicle idle.

Close Your Windows– Having your windows open increases wind resistance at high speeds. Keeping them closed can cut fuel consumption by three percent.

Take Out Unnecessary Weight– Leaving unnecessary items in your car, especially heavy ones, will decrease your gas mileage. An extra 100 pounds will decrease your miles per gallon by about one percent. It may not sound like much, but the miles add up! So check the trunk and take out anything that is unnecessary, if you have young children, leave the stroller at home unless you know you will absolutely need it.

Fill Up in the Morning– Gas is measured in volumes and not density. When you fill up in the morning the gas is cooler and as a result is more dense, so when you fill up in the morning you are getting more gas for your money.

Don’t Drive Aggressively– Rapid acceleration, hard braking, and speeding all waste gas. When you do it,  you lower your gas mileage by around five percent, and on the highway it is closer to 33 percent. Not only can avoiding driving aggressively save you money, but it is safer for you and other drivers on the road.


Keep Up with Vehicle Maintenance

Make Sure Your Tires Are Properly InflatedProperly inflated tires are not only safer, but they last longer and increase your gas mileage. Your vehicles gas mileage is lowered by 0.3 percent for every one psi drop in pressure of all four tires. Gas mileage can improve by 3.3 percent when you make sure that your tires are inflated to the proper pressure. You can find the proper tire pressure for your vehicle in your owner’s manual or on a sticker in the glove box or driver’s side door jamb.

Keep Your Engine in Top Shape– A healthy engine will get the best gas mileage. When your car has failed emissions or is noticeably out of tune, having it repaired can improve its gas mileage upwards of four percent depending on the repair and how well it was done. states that when you have a serious problem – like an oxygen sensor – fixed it can improve your gas mileage as much as 40 percent.

Use the Correct Motor Oil– According to, using the manufacturer recommended grade of motor oil in your vehicle can improve gas mileage by one to two percent. They also suggest that you look for motor oil that says “Energy Conserving” on the API performance symbol to be sure it contains friction-reducing additives.

Check Your Air Filter– Having a clean air filter makes it easier for your car to accelerate which in turn will use less gas. When you replace a clogged air filter you can improve your gas mileage by 10 percent. You can learn more about air filters here.

Check Your Fuel Cap– Nearly 147 million gallons of fuel evaporate every year because gas caps are not secured tightly. Listen for at least two clicks to make sure that your cap is secure. If your cap is lost or cracked, you should have it replaced.


Increased Gas Mileage in Hot Weather

Phoenicians know that more often than not, the temperatures in the Valley are on the warm side. The good news for us is that hot weather is actually better for your fuel economy than cool weather. The bad news is that the measures we take to stay comfortable – running the AC/rolling the windows down – while driving can have a negative effect on fuel economy. However, there are things that can be done to help minimalize the effect these measures have on our gas mileage. offers these tips:

  •  Roll the windows down at lower speeds; use the AC at highway speeds.
  • Don’t use the AC more than needed or set the temperature lower than needed.
  • Park in the shade or use a sunshade so that the cabin doesn’t get as hot
  • Drive with the windows open for a short time before using the AC. Letting hot air out of the cabin first will put less demand on the AC and help your vehicle cool faster.
  • Don’t idle with the AC running before driving. Turn the AC on after you begin to drive or after airing out the cabin briefly. Most AC systems will cool the vehicle faster while driving.
  • Read your owner’s manual. Most manuals explain how the AC system controls work and how to best use and maintain the AC system.
  • For plug-in hybrids and electric vehicles, pre-cooling the cabin while plugged into the charger can extend your vehicle’s range. Also, using a warmer temperature setting for the AC will use less battery power.

By following the advice above, you might notice that you fill up slightly less often than you were before, which will keep a little extra cash in your pockets. And who doesn’t like that?