Tips for Saving Fuel

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Cars.com photo by Evan Sears

If you're not ready to buy a more fuel-efficient car, you can still save money in a number of ways in whatever vehicle you drive. Cars.com provides the tips and dispels the myths.

Get the Lead Out: Weight is fuel economy's natural enemy, so removing unnecessary items or people from your car can translate to real fuel savings.

Get the Leadfoot Out: You can save fuel immediately in whatever you drive by going easy on the accelerator. Jackrabbit starts and full-throttle acceleration boost fuel consumption dramatically. It's a matter of degree: Light acceleration saves more than moderate acceleration.

Top speed also plays a part. Most vehicles are most efficient when cruising in their top gear at a relatively low speed. For example, a car with a six-speed transmission would be most efficient in 6th gear at 40 to 55 mph. Wind resistance increases exponentially with speed, so as your pace increases from this point, fuel economy drops dramatically. Onboard trip computers that show instantaneous and average fuel economy are remarkably accurate. Keep an eye on this and you'll learn how to drive in a miserly fashion.

An Ounce of Prevention: Keeping your tires inflated properly and your engine running right is critical to efficient motoring. Underinflated tires can lower your fuel economy by full miles per gallon. (Get the correct tire pressure amount from the sticker on your car's doorjamb or the owner's manual, and not the tire's sidewall.) Even if your car seems to be running well, that perplexing check engine light could represent a dead oxygen sensor or some other emissions control problem that causes the vehicle to waste several miles per gallon.

Open Windows or Air Conditioning: This is an age-old riddle. (Unlike a car's heater, which uses free engine heat to warm the cabin, the air conditioner robs engine power and lowers fuel economy.) Which approach is better? It's not as simple as one or the other.

If your car has been sitting in the sun and is hotter than the outside air, drive for a few minutes with the windows open to cool off. Then, if you're hitting the highway, close 'em up and turn on the air conditiong. Aerodynamics are more important at high speeds, so if you're not exceeding 35 or 40 mph, open windows won't make as much difference. It also depends on the vehicle. The detriment from driving with the windows down is greater, say, in a Chevy Corvette, which has excellent aerodynamics, than in a Jeep Wrangler, which has ... none. The same applies to convertibles; you'll burn less fuel with the top up.

Keep It Sleek: Speaking of aerodynamics, roof-top carriers and bike and ski racks don't do you any favors even when they're empty. If you keep all your cargo inside the car, you'll slip through the wind better. Also, remove aftermarket add-ons such as bug deflectors and window and sunroof wind deflectors. By design, these items work by wrecking your aerodynamics. Sure, bug entrails on your windshield are gross, but they don't cost you any fuel.

Premium or Regular: Lower octane costs less, but should you use it? Most modern cars that call for premium fuel can run on regular gasoline without knocking or any long-term penalty. Technically, this makes the car less efficient, but not to a degree that negates the cost savings from the cheaper fuel grade. NOTE: This is true of cars for which premium is recommended, not required. If in doubt, look for terms such as "for best performance" and "recommended" as opposed to "only" or "required." If your car has a turbocharger or supercharger, you should stick with premium fuel. Of course, if your car calls for regular gasoline, there's no reason to run it on anything higher in octane.

Fuel Efficiency

Executive Editor Joe Wiesenfelder, a Cars.com launch veteran, leads the car evaluation effort. He owns a 1984 Mercedes 300D and a 2002 Mazda Miata SE.  Email Joe