March 17 2010 by Chris McGinnis
By now everyone has heard the old adage that you don't save any money on gas by driving on the freeway with the air conditioner off and the windows down. (Having the windows down causes aerodynamic drag, which cancels out the effect of turning off the A/C.)
Since most readers of this blog do a lot of driving, I thought it might be time to put some other myths to rest.
First off, something we've probably all done recently due to the recent severe winter weather--the myth that you need to let your car engine warm up when it's cold outside.
"Your engine only needs a warm-up period of about 10 seconds - you're actually the only one who may feel chilly," said Dawn Paluszny at Ford Motors. "The engine warms up while you drive. Running your car any longer beforehand is just a waste of gas--and money."
Then there's the myth about having to change your car's oil every 3,000 miles. I'm a sucker for the sticker on my windshield that says just that. But the reality is different.
Paluszny says the 3,000-mile rule used to be true, but not with newer cars. "Because of newer synthetic oils that don't break down as quickly, consumers actually don't need oil changes as often - more like every 5,000 to 7,500 miles, depending on how you drive," she advises.
Here's another... I've always thought that the number listed on the sidewalls of my tires were the recommended tire pressure. That's not right. In most cases, that number is the maximum pressure allowed...the recommended amount is posted on the handy dandy little sticker on the inside door panel.
I've also heard that buying gas in the morning was smarter because that's the time gas is coolest and densest, meaning you get more for your money. Not true, either! Since gas is stored in 10,000-gallon tanks underground, the temperature remains constant all day. However, the adage does have some merit: "Pumping gas when it's cooler means less vapors are released into the atmosphere, which is better for the environment," Paluszny added.