Fred Flintstone’s ultimate gas-conserving vehicle by AdamL212

In the name of saving gas and money, fuel-efficiency tips are widely circulated. And while many of them seem reasonable, the advice is often misguided. I took a look at studies done to measure fuel efficiency to see which tips were really effective and which are just popular myths. Here’s what I found:

TOP 5 GAS-SAVING MYTHS

1) A.C. versus Windows Down

You may have heard that using your A.C. puts more strain on your engine and drains gas. In the other corner of the ring, there’s the theory that leaving the A.C. off in favor of rolling your windows down creates drag on the car that it must compensate for by—once again—using more gas. So which view is correct?

Both, according to Edmunds.com, but neither makes a big enough difference to factor into your cooling decisions. If you really want to save a few cents per gallon while staying cool, keep the windows up at high speeds and the A.C. off or on low, but blast the fans. And unlike open windows, open sunroofs cause a significant decrease in mileage.

2) Fuel Additives

Can gadgets and fuel additives help you save on gas? Not likely, says Stacey Bradford, associate editor at SmartMoney.com. The EPA tested over 100 of these products, from pills that you drop in the gas tank to devices that manipulate the fuel flow. Their results showed that these products didn’t help, and in some cases, can damage your car.

3) Filling Up in the Morning

One myth says that it’s better to buy your gas in the morning because the cooler temperatures make the liquid denser, resulting in more for your money. There’s some logic behind the idea, but don’t go changing your routine, says Consumer Reports. Most stations store their gasoline in underground tanks where the temperature varies little. A difference of 15 degrees caused only a 1 percent gain in gasoline volume.

4) Tailgating to Save Gas

Diehard gas conservationists may cite the technique of “drafting,” a stock-car racing strategy in which you pull as close as possible to the car in front of you to take advantage of the air-resistance-free zone behind it. But according to a CNNMoney.com article, you must be within 4 to 6 feet of the other vehicle in order for this technique to help—a dangerously dumb idea. And at such close distances, maintaining your speed is difficult. Sudden braking and lane changes results in wasting the gas you were trying to save.

5) Leaving Your Car Running
Most people agree that leaving your engine idling for long periods of time is no way to save gas. But what about shorter periods? One myth is that your car uses more gas to restart the engine than it does if you just leave it idling. This is not true for the modern vehicle. Consumer Reports recommends turning off the engine if you expect to be idling for more than 30 seconds; Edmunds sets the timer at a minute. —Kelsey Rexroat