As the temperature decreases this fall so does your tire pressure. Goodyear says that air pressure in a tire typically goes down 1-2 pounds for every 10 degrees of temperature change. Keeping the correct air pressure in your tires is critical. So-called under-inflation is a tire’s enemy because it causes increased tread wear on the shoulder or the outside edges. It also generates heat, and it can reduce fuel economy by increasing rolling resistance, since soft tires make the vehicle work harder.
In the notorious case of Ford and Firestone, under-inflation combined with age and high temperatures killed and seriously injured hundreds of people driving Ford Explorer, Mazda Navaho and Mercury Mountaineer SUVs in hot weather states. The problem was compounded by Ford’s late decision to lower ATX tire pressures to 26 psi because the Explorer failed an internal rollover test just before production started.
“Odds are that many motorists haven’t checked their tire pressure since the weather began turning cooler. If the last time the tire pressure was checked was during the heat of summer, many people could soon be riding on severely under-inflated tires,” says Steve Rohweder, Goodyear director of consumer tire technology.
To find the proper air pressure for a tire, look in the vehicle owner’s manual, in the glove box or on the driver’s side door jamb. The inflation pressure stamped on the sidewall of a tire is the “maximum” pressure, not the “recommended” pressure.
“Even though consumers can simply and quickly check the air pressure of their tires, it can be neglected,” Rohweder said. “That’s too bad, because the four patches of rubber that come in contact with the road surface are vitally important to the performance of the vehicle. They are key for acceleration, lateral traction and braking grip.”
The evolution of in-dash tire pressure monitor systems on new vehicles may alert drivers to significantly low tire pressure levels, but Rohweder likes the old-fashioned method of checking tire inflation for optimum tire performance.
“At least once a month, take a few minutes and check your tire pressure with an accurate tire gauge. You can’t tell if a tire needs air just by looking. It could be under-inflated by 10 pounds and still look fine,” he said.