TIRES: One for all?

In a perfect world, fleets would equip their tractors with all-position rib tires on the steer axle, as well as the inner and outer duals of the drive axle. The reason is fairly obvious: saving money. First of all, keeping just two types of tires in inventory — one model for steer and drive axles and another for trailers — is less expensive than keeping a variety of tires in stock. This is true whether a fleet is stocking its own inventory or a supplier is doing it for them.

In the second place, using rib tires can mean saving money on fuel. A good rib tire, which has less tread than a thicker drive tire, is going to produce less rolling resistance, translating into better fuel economy.

“That lower rolling resistance gives you tremendous fuel savings — a 3% to 5% improvement in fuel economy,” says Ron Gilbert, national director of sales-commercial tires for Toyo Tires. “You would need to rotate them more frequently back to front to help even out tread wear, but from the fuel savings alone you'd still be ahead.”

Finally, using an all-position rib tire all the way around the tractor saves a fleet big time in terms of tire pricing. “It'll save you $1,000 to $2,000 per power unit (about $100 per tire) using ribs all the way around, excluding the trailer axle position,” says Curtis Decker, manager of field engineering at Continental Tire North America (CTNA). “That's a big upfront savings.”

It all totals up to some pretty compelling reasons for a fleet to switch to an all-position tire, doesn't it? But since fleets don't operate in anything close to a perfect world, choosing all-position tires may be an option for only a very small segment of trucking companies, at best.

“We prefer to use position-specific treads, because our equipment runs in such a wide variety of applications — in-city pickup and delivery (P&D), regional runs, and long-haul operations across plains and mountains, with all different kinds of weather to contend with,” says Jim Law, national tire manager for truck leasing and maintenance giant Ryder.

“We want tires in P&D fleets to be able to withstand sidewall damage, or have tires with good traction for our customers that frequently operate in severe weather, such as snow, or who need to operate off-road as well as on-highway,” he says. “In our situation, with such a diversity of equipment, applications and operating environment, it makes sense to use position-specific tires.”

Doug Jones, customer engineering support manager at Michelin Americas Truck Tires, says the only time it's a good idea to use just all-position tires is “if a fleet's main concern is fuel economy, because they usually have a lower rolling resistance than drive and trailer tires.” He continues, “However, using specific-position tires…provides better handling and traction because they are optimized for those specific positions, and are also designed for better and longer wear.”

Phillip Boartes, marketing director for commercial products at Cooper Tire & Rubber Co., agrees that traction is one of the real pluses to using position-specific tires, along with longer mileage and better life cycle cost. He feels that the biggest benefit, though, is that they're designed to withstand the unique rigors of particular applications, such as off-road use.

“Take a tire that'll run 70% on-road and 30% off-highway, such as in a logging fleet. You'll need a particular tread and rubber compound to handle that — one that can withstand chipping and cutting,” he explains. “Chips and cuts wear out the tire early…you have a better chance of getting more life out of the tire [if you spec] a specific type. In the end, you need the right tire for the right application.”