Often overlooked and under-appreciated, trailer tires contribute a great deal to a tractor-trailer's performance. They play a major role in a rig's overall rolling resistance. And, if a trailer tire springs a leak, it can have a detrimental effect on a rig's basic movement.

As fleets continue to squeeze every penny out of their operating budgets, improving fuel economy and eliminating downtime remain leading trailer tire concerns, according to tire manufacturers.

Reducing Rolling Resistance

Reducing a tractor-trailer's overall rolling resistance is a major goal for most fleets, according to Bill Hoban, national truck tire sales manager for Cooper Tire & Rubber Co. And the message is getting out to dealers, he adds.

"I had a dealer call me today and ask what our rolling resistance numbers are. We're looking at compounding and casing construction" to achieve lower rolling resistance.

Along those lines, Hoban said Cooper is pursuing SmartWay certification from the U.S. Environmental Protection Agency (EPA), which may extend the certification to medium truck tire retreads (see sidebar).

"Trailer tires have been somewhat of a commodity item," said Roger Stansbie, director of tire technology, Commercial Vehicle Tires, the Americas, for Continental Tire North America Inc.

"From our observation, trailer tire manufacturers tend to choose fairly economical compounds," said Stansbie. To lower rolling resistance, "you have to start doing more engineering, especially when it comes to compounding. Another method is to really concentrate on your tread designs."

Trailer Tires Require Attention

"The biggest trend we see right now is everyone going green and trying to reduce rolling resistance," said Rick Phillips, manager of commercial sales for Yokohama Tire Corp.

Yokohama is developing a trailer tire for its eco-friendly Z.environment line, which currently only includes steer and drive axle tires. "Probably within the next year or two you'll see it on the market."

Trailer tires require as much attention as steer and drive tires, but don't often receive it, he explains.

"If you think about all 18 wheel positions on a rig, the driver gets immediate feedback from the steer and drive tires. The trailer is a separate vehicle. Trailer tires take more abuse and are more liable to experience en route failure than any other position.

"Also, a trailer tire may go from carrying 40 percent of the gross vehicle weight of the truck and then come home empty carrying hardly any weight."

Efforts are underway to lighten trailer tires, which, in turn, will lighten the overall weight of the vehicle, said Guy Walenga, director of engineering for commercial products and technologies, Bridgestone Americas Tire Operations LLC.

"Trailer tires are a place where you will see attempts made [to reduce weight]," he noted.

Sealed and Delivered

While fuel efficiency is a top fleet concern, Larry Tucker, marketing manager, long-haul tires, Goodyear Tire & Rubber Co., said the threat of downtime also remains a big problem, especially since overall freight movement is low.

To help in this arena, Goodyear recently put its DuraSeal self-sealing technology in the G395 LHS Fuel Max truck tire, the first time the company has built DuraSeal into a long-haul product. (Previously, DuraSeal was reserved for short-haul tires.)

Goodyear's decision to put DuraSeal in the G395 LHS was in direct response to fleet demands, Tucker said. "We do a fleet symposium twice a year with unsold customers. We pick their brains as to what keeps them awake at night. We found the number one issue was trailer tire flats. That's what gives them the biggest headaches."

The long-haul fleet owners surveyed by Goodyear had never heard of DuraSeal, according to Tucker. "They said, 'If you can put it in trailer tires, it would help us so much.' "