Six gas mileage myths

By Jim Motavalli
Posted Tue May 25, 2010 10:09am PDT


(Photo: Peter Dazeley)


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 That is a long-outdated notion.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.

Here's the complete list of myths.


More from The Daily Green

• Four Easy Tips to Boost Gas Mileage and Save Money
• Great Gas Mileage Is a Game
• The Smart Car Reviews: Good Gas Mileage and Surprises
• Getting 133 mpg in a 1998 Pontiac
• How Efficient Can Internal Combustion Get?

 

They forgot to add that eating beans will also give you gas.

 

LOL @ this list.

First off, back in the day when there were carbs it was more fuel efficient to not shut the car off and to leave it idle... so it's not really a myth, as just something that was outdated.

Second, I'm a FIRM FIRM FIRM believer of allowing a car to warm up before driving it. Your oil being cold and thick is not a good lubricator and when you drive you are putting the friction and stress where it shouldn't be. I'm not saying wait until it's 180-195°, but maybe 100° so the oil can properly be thinned out and where it needs to be. Also O2 sensors aren't working until the car is warmed up anyway, so the car really doesn't know how to adjust properly for fuel on a cold engine.

Third, a clean air filter allows unobstructed flow of air into your engine, that your car monitors and adds the proper amount of fuel. That's NEVER changed, why would you want to run a dirty air filter?

 

Funny they say important maintenance is required on an older car in order to maintain its fuel efficiency, but a dirty air filter isn't part of keeping up on that maintenance. Heh.

Secondly, I agree with Cibiblacksheep on letting the car warm up. I usually wait at least 20 seconds for my car when I start it up, even with synthetic oil.

As for letting the car idle...I kinda agree, I only turn the car off if I'm waiting for a train or something really long like that. Otherwise I put it in neutral or park while I'm waiting, heard somewhere that it's easier on the transmission to wait in neutral/park rather than Drive.

 

LOL, this came from Yahoo news huh!? I just saw this article...

I don't agree with all of what was said...a dirty airfilter? Come on, that makes no sense, the harder your car has to work to pull in air, the more fuel it uses, and the less power you will see.

As for warming up a car, its NOT neccesary to let it warm up to much, but I DO think you should at least give it 30 sec to get the oil flowing to all the moving parts before throwing it into drive. I usually wait 1-2 min on cold morning starts.

 

Yes, letting a car warm up is always a good idea. But it depends on whta the temp is outside. If is 50+ you just need about 45sec. If its below 50 you need about 2 min, thats all.

 

If it took 30 seconds for your engine to get oil to all the right places your engine wouldn't last long. It's pretty instantaneous that oil is flowing everywhere it needs to be upon start up.

Though as an engine wears throughout it's life it is possible it may need a little warm up time in the morning.

And the only reason carburetored cars ever need to warm up before driving is because of the very nature of carbs. They don't have the capability of making on the fly air/fuel adjustments. But hey, if you don't mind nursing the throttle you can take right off after starting a car running a carb, though it being a manual helps (or electronic assisted).

 

I believe in letting the engine warm up a little too. To let the oil circulate from the oil pan. In the summer I usually sit for about 30 seconds. In the winter, until the heater warms my azz up. LOL.

 

I had heard somewhere (source needed) that letting a car warm up can be a bad thing as it doesn't generate enough oil pressure at idle to fully lubricate all of the tight spots. Not sure which of the scale is right, but generally my car doesn't get much of a warm up, tho I try to avoid WOT going out of the garage.

 

I think after 10 + years and 169k letting it warm up isn't hurting anything lol