Six gas mileage myths

[Rodger Tellefson]

Here's the meat of the article:

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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 That is a long-outdated notion.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Another outdated claim, going back to the pre-1976 carburetor days.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.

 

[swshawaii]

They left out the biggest contributor of poor fuel mileage:



Heavy right feet and jackrabbit starts.

 

[Richard L]

swshawaii,

They left out the biggest contributor of poor fuel mileage:



Heavy right feet and jackrabbit starts.

They left them out because they are not myths...They are true and have always been true wasters of gas. :supercool:



...Rich

 

[swshawaii]

Geez, I overlooked the key word in the post header. (Myths)

Thanks Richard, I'll read the whole sentence next time. :smack:



sws

 

[Chris Rice]

One that I didn't know what the clean air filter...I thought a real dirty one would hurt mpg. I make sure to keep mine clean, and still will.

 

[Johnny O]

Yeah, I don't buy the part about not needing a clean air filter. That said, today's air filters have a lot more sq. in. of filter area for the displacement of the motor than they did 30 years ago so I don't think you need to change them as often. I clean the K&N in my truck once a year regardless, the stocker in my wife's Taurus says to change every 30k and frankly after 30k it ain't all that dirty.

 

[Sandy Curry]

I can disprove the age equals less mileage myth! 2001 4x4 with 170,000 miles and 34 oil changes later (every 5000) still getting about 20 miles to the gallon. Air filters often enough, but oil always on time.

 

[scott degroot]

While a clean air filter is alwasy a good thing, it's true that on a fuel injected vehicle it really doesn't affect fuel mileage. It's all in the electronics. You need a certain amount of fuel for a certain amount of air, now if you cut down the amount of air adn reduce the amount of fuel at the same time you really aren't hurting anything other than max engine output. On carbuerated vehicles you had no way of reducing the amount of fuel unless you rejetted the carb, so a dirty air filter would affect fuel economy as you were getting less air but still putting in the same amount of fuel.

 

[Dreman]

228,000 miles and still get 400 or so miles per tank. Every time.