HILTON HEAD, S.C.—“New-tires-on-rear” is a universal axiom propagated by tire manufacturers, according to John M. Baldwin, principal scientist at Exponent Engineering.
But extensive testing, plus a thorough review of accident and fatality statistics, doesn’t necessarily demonstrate that placing new tires on the front of a vehicle is always dangerous, Baldwin said in a speech at the 28th annual Clemson University Tire Industry Conference in Hilton Head April 18-20.
Baldwin, who at the time of the speech was moving to a new position at Discount Tire Co. Inc., also called out the Rubber Manufacturers Association for what he said was a mischaracterization of the tire aging research he performed while working as a tire research specialist at Ford Motor Co.
In his speech, Baldwin evaluated common tire industry policies from the perspective of tire retailers.
“In the tire industry, a lot of decisions are based on tread depth,” he said. “But what is the significance of tread depth? There is uneven wear on damn near every tire.”
The general rule of thumb, Baldwin said, is to replace a tire when it reaches 2/32 inch of tread depth. “But you don’t know what part of the tire you’re at,” he said. “It could be the best or the worst part of the tire.”
Tire age also can’t be left out of the equation, according to Baldwin. Based largely on the results of Baldwin’s testing, Ford recommends that vehicle owners replace their tires after six years regardless of the tires’ remaining treadwear.
“The average full-sized spare tire is nine years old,” he said. “You can tell your tire store to take that perfectly good spare tire and put it on your car. But if you’re in Yuma or Miami, do you really want that nine-year-old spare going on?
“Meanwhile, the average mini-spare is 12 years old. That means you’re screwed.”
As for new tires, the RMA position is that they go on the rear of a vehicle unless the tires have a low speed rating, Baldwin said. This common wisdom is backed by videos by Tire Rack, Michelin North America Inc., Continental Tire the Americas L.L.C. and others depicting the dangers of fitting two new tires on the front of a vehicle.
“The industry’s position is that if you put two new tires on the front, you are going to die,” he said. “The absolutism of this is astounding to me.” (continued)
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