Six gas mileage myths

Do Americans care about fuel economy as oil spills into the Gulf of Mexico and gasoline hovers around $3 a gallon? You bet they do, though they also have a fair number of misconceptions about how to squeeze a few more miles out of every drop.
 The Consumer Federation of America's (CFA) most recent survey says that if we had a 50-mile-per-gallon car fleet today, we'd save more oil than the entire proven reserves in the entire Gulf of Mexico. And people care about that.
According to Jack Gillis, author of The Car Book and a CFA spokesman, 87 percent of respondents said it is "important that the country reduce its consumption of oil," and 54 percent said it is "very important."
An amazing 65 percent of Americans surveyed support a mandated transition to a 50-mpg fuel economy standard by 2025. That's a tough standard, some 15 mpg better than the ambitious goal set by the Obama Administration (35 mpg by 2016).
"The expectations of American consumers are reasonable and achievable," Gillis said in a conference call." CFA says that Asian carmakers, compared to the U.S. competition, are offering twice as many vehicles with 30 mpg or better. "It's shocking that so few of today's cars get more than 30 mpg," he said.
Mark Cooper, CFA's research director, noted that in five years of the group's polling, the public's views have stayed remarkably consistent: Americans want less dependence on Middle Eastern oil and higher fuel-economy standards.
People care about fuel economy, but they're misinformed about how to actually achieve it. The federal government's fueleconomy.gov site (very useful to check cars' mpg) just published the "Top 10 Misconceptions About Fuel Economy."

Here are a few big myths:
•It takes more fuel to start a vehicle than it does to let it idle.
People are really confused about this one and will leave a car idling for half an hour rather than turn it off and restart. Some kids I know started an anti-idling campaign in the suburbs and are shaming parents into shutting down their cars.
Idling uses a quarter- to a half-gallon of fuel in an hour (costing you one to two cents a minute). Unless you're stalled in traffic, turn off the car when stopped for more a few minutes.
•Vehicles need to be warmed up before they're driven.
Pshaw. That is a long-outdated notion. Today's cars are fine being driven off seconds after they're started.
•As a vehicle ages, its fuel economy decreases significantly.
Not true. As long as it's maintained, a 10- or 15-year-old car should have like-new mileage. The key thing is maintenance -- an out-of-tune car will definitely start to decline mileage-wise.
•Replacing your air filter helps your car run efficiently.
Another outdated claim, going back to the pre-1976 carburetor days. Modern fuel-injection engines don't get economy benefits from a clean air filter.
•After-market additives and devices can dramatically improve your fuel economy.
As readers of my story on The Blade recall, there's not much evidence that these "miracle products" do much more than drain your wallet. Both the Federal Trade Commission and Consumer Reports have weighed in on this. There are no top-secret 100-mpg add-ons out there.
•Using premium fuel improves fuel economy.
You might as well write a check to BP if you believe this. Only use premium if your car specifies it.