Going Wide (January 01, 2006)

by Adam Ledlow

BOSTON, Mass. – Let’s say a tire company approaches you with a way to save four per cent in fuel costs and chop more than 750 lbs from your total tire weight. If those numbers aren’t enough to impress you, the company’s also boasting increased ride comfort, improved handling and stability, and easier maintenance. Sounds like a dream come true, right?

These are the very figures being put forth by Michael Burroughes, product portfolio manager, Michelin North America, with its new generation of wide single tires, the X One.

“The whole idea behind this is to increase or improve the overall productivity of the trucking industry,” he told an audience at the American Trucking Associations’ Management Conference and Exhibition in Boston.

Unfortunately, there’s a catch.

While wide single tires can be seen all over European roads and have also been steadily moving into the U.S. market, if you a want to use these tires to run freight in Canada, you’re going to get slapped with some hefty load restrictions – at least for now.

“It’s legal to run (X Ones) in every single Canadian jurisdiction, but the problem is there are load restrictions that make them uneconomical,” said Ralph Beaveridge, marketing manager, Michelin North America.

Essentially, the weight restrictions imposed by the Canadian government are in place to protect the country’s roads and highways. The concern of possible road damage from using wide single tires instead of traditional duals stems not from the X One, but rather an older generation of single tires formerly found on dump trucks and cement mixers. Given the statistics outlining the road damage caused by these old-model tires, Beaveridge said he can hardly blame the government for its apprehension to singles.

“Those older generation tires have been proven to cause significant damage to infrastructure,” he said. “We’re not talking 10, 15, 20 per cent. We’re talking between 200 and 700 per cent.”

At present, the restrictions allow no more than 3,000 kg per tire for a maximum total of 12,000 kg per axle. So if a truck runs with singles instead of duals, with only two tires per axle instead of four, the truck would be limited to 6,000 kg per axle. With an average application in Canada running at about 9,000 kg per axle, a truck using singles under these rules would be severely hindered as to what it could haul.

“Even potato chips weigh more than that,” Beaveridge said.

Aware of the flaws of the road-eating wide single tires of the past, but confident in its new line of tire technology, Michelin sponsored some tests at Virginia Tech to pit the single model against the longstanding dual configuration.

“The conclusion of the testing (showed) very clearly that the new generation single tires are damage neutral compared to duals. In other words we have the same impact as duals both on the surface and the substructure of the pavement,” Beaveridge said.

Despite what appeared a victory for the single tire, after submitting the results to the Council of Deputy Ministers Task Force on Vehicle Weights and Dimensions, there was another setback. The council expressed concern that the Virginia Tech testing was not applicable to the Canadian environment because they were on U.S. roads with U.S. configurations.

Taking the council’s concerns into account, Michelin took things a step further creating an elaborate model to run data on different frequencies, pavements and loads to compare to the U.S. findings.

The results? In the worst case scenario there was only about a two per cent increase in impact, a number Beaveridge said is miniscule on the grand scale.

In addition to the Virginia Tech testing, the Transportation Research Board completed a study that looked at the tire population across North America.

The study found that 68 per cent of duals operating on the roads had pressure between the two tires within 10 per cent. That means the remaining 32 per cent of duals with a pressure difference of more than 10 per cent have one tire carrying between 55 and 70 per cent of the load. Of even greater concern was that more than 15 per cent of duals had a difference in pressure of over 20 per cent, meaning one tire was carrying the entire load.

“We felt that that redeemed the second generation of single tires. It really proved that the concerns about damage were misplaced,” Beaveridge said.

Though Michelin has been fighting with regulators for years to ease weight restrictions in a frustrating and seemingly unending bureaucratic process, the X One’s integration doesn’t seem too far away. The industry should probably expect to see a major change in tire regulations within two years, Beaveridge said.

“At this point, it’s just resistance to the truth,” he said. “The bottom line is the technology works and it works extremely well. It’s not just something that has tremendous benefits for the trucking industry, but for society in general.”

But not everyone is convinced. Bridgestone and Goodyear have both created a wide-based single tire as well, but they aren’t as sold on the concept as Michelin.

At a recent Ontario Trucking Association (OTA) panel discussion, the manufacturers said wide-based singles are only recommended for specialized, niche applications.

Brian Rennie of Bridgestone/Firestone Canada suggested that fleets looking to shave fuel costs through tire selection would be better off spec’ing a fuel-efficient dual tire.

He said the only real benefit of running wide-based tires is the weight savings – weight savings that aren’t achievable under the current regulations.

But even south of the border where no such weight penalties are imposed for those running wide-based single tires, Rennie said there’s still only a niche market for the singles.

Al Cohn of Goodyear said even when the weight restrictions are lifted, there will be very little benefit to running wide-based singles.

He points out wide-based tires don’t last as long as duals (one customer reported getting only 129,000 miles on singles compared to 180,000 on duals), come with a higher cost-per-mile, and aren’t as retread-friendly.

“These tires cannot get two retreads – if everything is perfect you may get one,” he said.

He also pointed out the tires do not perform well when underinflated (they won’t run when underinflated by 10 per cent he said) and they’re not easy to work with.

“You need to be like Paul Bunyon to pick up and handle this wheel,” he said.

Rennie added availability is another problem worth considering before making the switch.

“Try to find these tires in Wawa, Ont. – good luck,” he pointed out.

Rennie admitted there’s one application where wide-based singles would be recommended in Canada.

That’s a dedicated run to the U.S. where lower axle weight allowances make the Canadian penalties a non-issue.

Rennie points out “It’s still a niche product in the U.S., even without the weight restrictions.”

Despite the conflicting messages, Beaveridge insisted the weight penalties should be lifted so customers can draw their own conclusions.

If that’s the case, he said he’s convinced drivers will be the ones who make wide based singles an industry norm.

“Without exception, every driver who has driven the X One has said that without a doubt it’s the most comfortable ride,” he insisted.

Have your say

We won't publish or share your data