Recommended Tread Depth

Tread depth debate goes on

By: Kathy McCarron

Tire Business October 22nd, 2007 YONKERS, N.Y.

In its November issue, Consumer Reports recommended consumers use a quarter instead of a penny to measure tread depth - a change that effectively doubles the depth at which car owners should consider getting new tires from 2/32 to 4/32 inch.

In making its recommendation, the magazine cited its own and others' research that show braking distances in wet weather increase markedly after tires reach the 4/32-inch mark.

For some tire dealerships, this recommendation by an influential publication won't change how they recommend tire replacements, but it might back them up in the eyes of the customer.

Parrish-McIntyre Tire Co. in Akron has recommended replacement at 4/32 inch tread depth for years. "2/32 is considered bald,'' said Jon Schadel, supervisor of stores.

"I'm not surprised by (the CR recommendation),'' said Drew Dawson, owner of Tire Source in Copley Township, Ohio, saying it's not a bad standard for the industry.

"It depends on the time of year. If you go 4/32 into the spring and summer months, especially summer past the rainy season, it's safe. If it's 4/32 as you go into the winter months in Northeast Ohio, the customer is not as confident'' of the traction capabilities.

Tire dealers said that many tires need to be replaced long before they reach the 2/32-inch tread depth anyway.

Randy Jones, president and CEO of Tireman Auto Services Centers in Toledo, Ohio, said more often than not his technicians recommend tire replacements due to uneven wear rather than low tread depth.

"Two out of four tires usually show uneven wear. That's what usually forces us to recommend replacement,'' he said.

But if tires show even wear, he thinks a tire with 4/32-inch tread depth still has wear left.

Mr. Jones said his customers usually don't come in with tread depth concerns but rather with symptoms, such as lack of traction or hydroplaning. The usual explanation is uneven wear, even when there is tread left, he said.

"Tires wear so differently,'' Mr. Dawson added. "Some get more wear on the edges that keep people from getting to the 2/32.''

Tireman's Mr. Jones said his customers are more willing to replace tires to attain traction capabilities. "Most consumers want to replace in sets (of four) for better performance.''

However, "a lot of tire dealers are hesitant to recommend (early replacements) because it will look like a dishonest recommendation,'' Mr. Jones said.

There is a percentage of customers who follow CR's recommendations for their tire purchases, according to the tire dealers contacted by Tire Business.

So Tire Source's Mr. Dawson preferred that CR promote the 4/32-inch minimum tread depth, rather than the tire industry. "In my thinking, it's equivalent to if the manufacturer of toothbrushes came out saying you should replace your toothbrushes every 30 days. It appears self-serving. The fact that a leading consumer publication recommended (minimum tread depth) carries more weight than if we as the tire industry came out and said it.''

There is no national law governing minimum tread depth, but 42 states consider 2/32 inch the minimum legal tread depth. California and Idaho consider 1/32 the minimum, and Arkansas, Montana, New Mexico, North Dakota, South Carolina and West Virginia have no standards on tread depth.

In Canada, the minimum tread depth of 2/32 inch for cars/light trucks is a federal standard, enforced by local police under the authority of the Motor Vehicle Safety Act, according to information from the Rubber Association of Canada.

However, in Texas vehicles with tires below 3/32-inch tread depth cannot pass the state-mandated safety inspections, according to Phillip Nussbaum, president of A to Z Tire & Battery Inc. in Amarillo, Texas. Tread depth safety is often dependent on seasonal conditions, applications and even a customer's budget, he said.

In areas with a lot of rain, for example, lower tread depths are more susceptible to hydroplaning, Mr. Nussbaum said.

He said he believes the CR recommendation could impact tire replacement sales "to a degree.'' "Anything having something that makes customers more aware of safety helps,'' he said.

"When a leading publication like that says it, it certainly can't hurt. When a tire is at 3/32 and 4/32, it doesn't look as good and when you show it to the customer, they recognize that,'' he said.

In a sidebar to a test of high-performance tires in the November issue, CR urges consumers to insert a U.S. quarter, with George Washington's head down, into a tread groove. "If your tread doesn't cover Washington's hairline, it's time for new tires,'' the magazine said.