Want Better Fuel Economy?

By Tom Ripley

With fuel prices reaching new high levels, the average consumer's level of pain is also reaching new heights. In reaction to that many motorists are considering buying a hybrid vehicle, a sub-compact or even resorting to more drastic measures like ride-sharing or -- dare we say it -- walking.  Others are looking for significantly better fuel economy from a gizmo they or their local mechanic installs under the hood.  But the best solution to getting better fuel economy is among the least obvious ones to American drivers -- their tires.

Because today's tires are so high-tech and last so long, consumers have a tendency to forget that they need periodic checks.  It is not only a fuel economy issue; it is also a safety issue.  National Highway Traffic Safety Administration statistics show that nearly one out of every three vehicles on the road has a significantly under-inflated tire.  Why is that important?  Nearly 660 fatalities and 33,000 injuries occur every year as a result of low-tire-pressure-related crashes.
 
Despite these statistics, though, the typical driver doesn't pay much attention to his or her tires.  Research shows that about 85 percent of drivers don't properly check tire pressure.  And simple eyeballing of your tires as you get into or out of the car is not enough.  It is nearly impossible to tell if today's radial-ply tires are low in pressure simply by looking at them.  Instead, you should acquire a tire gauge and check your tires' pressure at least monthly.
 
"Not knowing the condition of your vehicle's tires is equal to pouring money down the drain," said the Auto Club's Principal Automotive Engineer Steve Mazor. "Proper tire inflation is necessary for safe driving and to reduce gas costs."
 
While air for your tires is free -- that's one thing the government hasn't figured out how to tax yet -- gasoline is growing ever more expensive, so those consumers who let their tires go low are spending needless money on fuel, and they might be driving their vehicle in an unsafe condition.  Just a little air in the tires can make all the difference in the world.

"Under-inflated tires can cut fuel economy by up to two percent per pound of pressure below the recommended level," said Mazor.

During every other fill-up motorists are well-advised to walk around their vehicles and check tires for uneven or excessive tread wear and proper inflation. While the eyeball is a good guide to determine if uneven or excessive wear is taking place, a tire pressure gauge is required to check inflation properly. Not certain what your tire pressure should be?  Drivers can refer to the vehicle's doorjamb or glove box for original tire inflation specifications. 
 
And while you're in the process of saving money it is not a bad idea to try to save your life as well.  Lack of tread depth can be dangerous, because your car won't handle properly, especially in wet weather.  In response to this, many states have minimum tread depth laws. Passenger cars might not operate safely on tires whose tread depth has dropped below 2/32-inch.

To determine if new tires are needed, the Honest Abe test is so simple even those of us who live in France carry a penny around as our tread depth gauge. The procedure is easy -- place a U.S. penny, Lincoln's head first, into several tread grooves. If part of Lincoln's head is covered by tread, then more than 2/32-inch tread depth remains, and that's good. If you see all of Honest Abe's head, though, you should purchase new tires.  When you purchase the new rubber, ask the tire store expert about tires that can help you maximize safety and fuel economy.  And be sure replacements meet manufacturers' speed/load specifications for your vehicle.

Driving Today Contributing Editor Tom Ripley writes about the auto industry and the human condition from his home in Villeperce, France.