Is Wider Better?

Michelin Leads Super Wide Charge in North America

With the introduction of a new breed of radial truck tires in North America, dual fitments on line haul fleets may become a thing of the past.
Best described as “super wide” tires – not to be confused with bulky conventional-sized wide base tires commonly used in high-load short-haul applications ®“ these drive and trailer units take the weight-saving benefits of low profile medium truck tires to a new level.
This past November, Michelin Americas Truck Tire (MATT) unveiled its new X-One super wide radial. MATT claims the X-One, specifically designed for long-haul applications, can reduce a Class 8 tractor/trailer’s weight by some 1,000 lbs, and deliver 5% in fuel savings if used in both drive and trailer positions.
Best of all, MATT’s super wides require no physical changes to the tractor or trailer. The X-One can be put on a drive or trailer axle as soon as the duals are removed, without any changes to the configuration whatsoever. Each X-One comes with an 14-inch aluminum wheel, specifically designed for the tire by Accuride, that matches the dimensions of existing dual assemblies.
“You can literally pull off a set of duals and put an X-One on and run a mixed axle,” said Lynn Mann, Michelin’s public relations manager.

Replacing LP Duals

The 455/50R22.5 X-One replaces a set of low profile 22.5-inch drive or trailer tires, and has a 17,000-pound rating per axle at 100 psi. Its fuel economy comes in part from reduced sidewall flexing compared to a set of comparable duals, and from low rolling resistance tread designs and compounds.
The tire weighs considerably less than its dual counterparts, allowing trucks to carry an additional 800 to 900 lbs more payload. MATT testing also shows the X-One tire/wheel assembly promotes cooler running brakes.
The casing features a continuous InfiniCoil belt that stabilizes the tread area and lengthens casing life, according to MATT. Michelin Retread Technologies, MATT’s sister operations, has already developed processes, materials and tread stock to allow retreading of the X-One.

Under Development

Other tire makers are trailing a bit on the development of commercial super wide tires for North American line haul applications, although most of them have had European versions for some time.
®′ Continental Tire North America is currently developing a Continental-branded super wide, the company said, with a target release date in 2003.
®′ Bridgestone/Firestone (BFS) said it plans to bring its Greatec line of super wide tires to the U.S. soon, and plans to unveil details on the tire, available sizes and an availability date at the Mid-America Trucking Show, Mar. 22-24 in Louisville. The Bridgestone Greatec is already being marketed in Europe and Asia.
®′ Toyo Tires USA Inc. currently has a line of wide base tires available for high-load capacity vehicles like dump trucks and mixers, and said it will develop a line of super wide tires based on market acceptance and conditions.
®′ Goodyear Tire North America said it has reservations about developing the super wide concept for North American tractor-trailers, although it has had a successful European version for quite some time.

Is The Market There?

Some of the companies have shied away from the concept, in part, because at present they see super wide tires making up only 5% of the U.S. medium truck tire market. Concerns about retreading support, wheels and availability have also played in their decisions to slow development of the tires.
At the same time, none have ruled out the idea of bringing super wide tires, which have been quite popular for lighter European trucks for some time, to these shores.
“We certainly are studying the concept in terms of customer needs,” said Dave Beasley, Goodyear’s general marketing manager for commercial truck tires. ®We don’t see a broad market application right now for this tire in a line-haul fleet. We haven’t seen fleets really requesting this type of concept. But if customers had a greater interest and desire, we would be happy to develop it.®
Toyo’s Earl Knoper, senior vice president of marketing, said roughly the same thing: “If the market expands, we can certainly expand our size line,” he said. ®Right now, we don’t see the market expanding rapidly.®
Continental’s plans include a 455/50R22.5 to replace two 295/75R22.5-sized tires. The tire will be available for both the drive and trailer positions. The company’s parent firm, Continental AG,  has had success with a similar European tire.
“Right now it’s a very successful product in Europe,” Cara Junkins, who is developing the tire concept at Continental Tire’s Mt. Vernon, Ill., facility, said.
“Now it’s just a matter of trying this concept here and getting market acceptance. We’ve had some interest from fleets, some calls, some questions. But we’re not at the point yet of getting a big program together to promote the product,” Junkins said.
“We’re a little bit farther out than Michelin – we’ve been evaluating the option to bring this to the U.S. market for about a year.”

Overcoming Obstacles

MATT devoted considerable time to overcoming obstacles that have faced this type of concept in the past, including cost, mounting practicality, lifecycle cost, and other issues.
The X-One costs the same as a traditional dual set, is easy to mount on existing vehicle configurations, and was specifically designed for tandem axle long haul applications, as opposed to the short distance, heavy load applications the wide base tires have been used for in the past.
Over 20 fleet tests – including testing with Freightliner ®“ have been conducted with the tire, according to MATT, and have racked up over 200 million road miles. No excessive downtime due to tire-related problems have been reported, according to the company.
The fuel savings possible with the X-One was also monitored by the test fleets for 18 months, and the tire seems to have stood up to the test. “Compared against our most fuel-efficient duals – and they are the most efficient on the market ®“ the X-One delivers a proven 5% fuel savings when in both the drive and the trailer positions,” Mann said.
  Mann said the another advantage of the X-One is that a single tire makes it more accessible for maintenance, and thus keeps a truck on the road longer without developing air pressure-related problems.

Easier Maintenance

   “If you were to go to drivers or fleet maintenance managers and ask them: ‘Of the set of duals, which tire is the problem tire?’ I’ll bet they would overwhelmingly say it was the inside tire,” Mann said. ®It’s difficult to crawl underneath the vehicle to check inside tires for tread wear, air pressure or other damage. You can’t always see what’s going on with the tire – it’s simply not accessible. A single tire solves that problem ®“ it’s much easier to check.®
   In addition, with fewer wheels, there are fewer tires to mount, dismount, inspect and rotate, resulting in less maintenance and vehicle downtime, according to MATT.
And in the case of an emergency, the X-One is available on the road nationwide at MATT dealers and at Truckstops of America locations across the country. And as a last resort, truckers can always put a set of dual low-profile R22.5s on with ease, as long as the tractor or trailer is set up with hub-piloted assemblies.
Currently, the X-One XDA drive tire is available as an OE option on 6×4 tractors from Freightliner, Sterling and Western Star, while the X-One XTA trailer tire is available as an OE option through major trailer manufacturers.