Increased Mileage

By changing your driving habits you can improve fuel economy up to 37 percent right away (depending on how you drive). Combine several tips and perform routine maintenance and you will save real dollars, not just pennies.

The wonderful part about what we found is that improving your car’s mileage is just a matter of changing your habits. Stack a few of these winners together and we’ll bet that you’ll see a substantial savings at the pump — without the need for a new car.

Test #1 Aggressive Driving vs. Moderate Driving

Result: Major savings potential

The Cold Hard Facts: Up to 37 percent savings, average savings of 31 percent

Recommendation: Stop driving like a maniac.

Test #2 Lower Speeds Saves Gas

Result: Substantial savings on a long trip

Cold Hard Facts: Up to 14 percent savings, average savings of 12 percent

Recommendation: Drive the speed limit.

Test #3 Use Cruise Control

Result: Surprisingly effective way to save gas

Cold Hard Facts: Up to 14-percent savings, average savings of 7 percent

Recommendation: If you’ve got it, use it.

Test #4 A/C On, Windows Up vs. A/C Off, Windows Down

Result: Nice in theory; not true in practice

Cold Hard Facts: No measurable difference (unless you open the sunroof, too!)

Recommendation: Please, make yourself comfortable.

Test #5 Check Your Tire Pressure

Result: Important for safety and to reduce tire wear

Cold Hard Facts: No measurable effect on the vehicles we tested

Recommendation: Check your tire pressure often but don’t expect a big savings.

Test #6 Avoid Excessive Idling

Result: More important than we assumed

Cold Hard Facts: Avoiding excessive idling can save up to 19 percent

Recommendation: Stopping longer than a minute? Shut ‘er down.

Test #1: Aggressive vs. Moderate Driving

This is gonna hurt. Our tests showed that the most significant way to save gas is: you. And we’re talking massive fuel economy gains. Think you need a hybrid? Chances are you’ve got hybrid-style mileage in your gas pedal foot. Don’t mash the gas when you start up. Take the long view of the road and brake easy. This tip alone can save you unbelievable amounts of gas. If you slowed your 0-to-60-mph acceleration time down from your current 10 seconds to a more normal city pace of 15 seconds, you’ll feel the savings immediately.

Test #2 Lower Speeds Saves Gas

Remember a thing called the speed limit? On most highways it is either 65 or 70 mph. How fast are the cars and trucks around you going? From 75 mph to 90 mph. These people are wasting a lot of gas for the chance to get there a little earlier. Factor in safety concerns and a speeding ticket once or twice a year and going fast is a costly proposition.

Test #3 Use Cruise Control

Using cruise control is a bit of gas-saving advice frequently on tips lists. We have always agreed with this tip in theory but we hadn’t expected such significant results. First, it smoothes out the driver’s accelerator input by preventing nervous “surging.” Second, it makes the driver take the long view of the road rather than reacting to every change in the traffic around them.

Test #4 A/C On, Windows Up vs. A/C Off, Windows Down

This has got to take you back to the days with the family on vacation. Dad says, “Turn the A/C off! It wastes gas!” And Mom says, “We can’t roll the windows down or everyone on the highway will think we can’t afford A/C.” And you’re in the back roasting, hoping someone will win the argument so you can cool off.

Well, family psychology aside, if dads are still saying this, they aren’t necessarily right. While the A/C compressor does pull power from the engine wasting some gas, the effect appears to be fairly minimal in modern cars. And putting the windows down tends to increase drag on most cars, canceling out any measurable gain from turning the A/C off. But this one depends on the model you’re driving. When we opened the sunroof in our SUV, the mileage did decrease even with the A/C off. Still, in our experience, it’s not worth the argument because you won’t save a lot of gas either way. So just do what’s comfortable.

Test #5: Check Your Tire Pressure

No matter how many times drivers hear about the importance of tire pressure, most of them don’t do anything about it. They probably don’t like squatting beside their car in a busy gas station with fumes swirling around them. But is it important? The answer is yes, for a number of reasons. Properly inflated tires are less likely to fail at high speeds. They wear more evenly and, yes, they deliver better gas mileage. How much? In this test we saw a modest difference in two of the cars. It might have been more dramatic with different tires on different cars. Experts swear by it; we couldn’t really document it. And we wound up wondering if tire technology, like the design in other areas of the car, had improved.

Eventually, we concluded that each set of tires is different and every vehicle is different. We recommend that you do your own tests to see what inflation setting gives you the best fuel economy.

Test #6 Avoid Excessive Idling

If you turn off a light bulb as you leave the room you’ll save electricity. If you turn off your car you will save gas. Obviously. But related questions are more difficult to answer. If you’re only stopping for only a minute, is it better to shut off the engine or keep it idling? Should I shut off the engine in traffic? How much gas will this save? What rule of thumb do I use when trying to save gas this way?