How to Optimize Gas Mileage

With gas prices seemingly always on the uptick, people are on the lookout for ways to make a tank of gas last longer. While you can opt to walk or bike, purchase a new, more fuel-efficient car, carpool or take public transportation to cut gas costs, such options aren’t realistic for many drivers. However, there are several other ways to optimize gas mileage, most of which involving a change in your driving habits.

Drive Slower

Not only is driving at posted speed limits potentially safer, but it’s also a gas saver. For instance, the U.S. Department of Energy estimates that for every 5 mph you drive over 50 mph, it costs about 24 cents more per gallon of gas. That’s because gas mileage decreases the faster you drive and it decreases most rapidly after you hit 50 mph. By driving at posted speed limits, you may be able to make a tank of gas last up to 14 percent longer.

Don’t Drive Aggressively

Hard braking and fast starting are killers to your gas tank. In fact, the U.S. Department of Energy estimates that these types of aggressive driving behaviors can put your gas tank on empty about 33 percent faster. So to make your tank of gas last longer, work on gradually starting and gradually stopping. You can gradually brake by better anticipating traffic lights by looking at the crossing signals. If you’re coming to an intersection and the cross walk signal is telling pedestrians to stop, the light is about to turn red.

Shift to High Gears

If you drive a stick, shift into the highest gear possible, even if you’re traveling at low speeds. According to Car Talk, doing so forces you to drive with the throttle plate further open, which decreases fuel-sapping vacuum in the intake manifold. The resultant reduction in “pumping losses” means that you burn less fuel. Although shifting sooner will sacrifice acceleration, you can always downshift if you need to speed up suddenly. Manual transmissions are generally more efficient than automatics.

Going Uphill

Although it feels natural to hit the accelerator when going uphill, you’re actually just making your engine work harder. And as you’re making your engine work harder, your gas mileage decreases rapidly. According to Money Talks News, while cruise control makes a tank of gas last 14 percent longer on level terrain, when you drive uphill cruise control forces your car to accelerate, and you burn more gas. Still, the reduction in pumping losses from opening the throttle further means that you’re actually running more efficiently for the amount of work required. Ultimately, you’ll save more fuel by slowing down going uphill — but no more than you would on flat terrain.

Stay Away from Ethanol

Adding ethanol to fuel mixtures reduces the country’s dependency on foreign fuel. According to the U.S. Energy Information Administration, most gasoline has about 10 percent ethanol in it. However, one downside to mixtures with 10 percent ethanol is that it reduces your gas mileage by as much as 3.3 percent. So to optimize your gas mileage, fill up at stations that don’t have ethanol in their fuel. If you can’t find a station that carries ethanol-free gas, go with the lowest percentage possible — usually E10, or ten percent ethanol.

References

Car Talk: Guide to Better Fuel Economy
Money Talks News: The 4 Best Ways to Improve Gas Mileage
Department of Energy: Energy Efficiency and Renewable Energy: Driving More Efficiently
Energy Information Administration: How Much Ethanol is in Gasoline and How Does it Affect Fuel Economy?

Resources

Pure-Gas.org