Michelin makes the case for wide-base singles

by James Menzies

WATERLOO, Ont. –Spend a dime, save a buck? It’s a pretty intriguing value proposition, touted by Michelin when discussing its widebase single tire, the X-One. A couple of factors have developed recently, which have led the tire company to adopt the new tag line.

For one, wide-base tires are now more widely accepted in Canada. A Memorandum of Understanding inked by the Council of Ministers Responsible for Transportation and Highway Safety in July has paved the way for the more widespread use of the tires. They can now be used to haul US-legal weights from coast-to-coast in Canada, albeit with a few regional exceptions.

At the same time, the unprecedented cost of fuel has also changed the value proposition for wide-base tires. For every dollar spent on tires, a fleet or owner/operator spends about $25 on fuel. The X-One has proven to deliver a 4% fuel mileage improvement in most applications, according to Michelin, hence its latest slogan -spend a dime, save a buck. (The X-One costs about 10% more up-front than a set of duals).

The current high cost of fuel, combined with the MoU which lifted prohibitive weight restrictions on wide-base singles, meant the time was right for Michelin to hit the road and spread the word about its wide single tires.

The Go Wide, Save Green demonstration event was held throughout North America this summer, with a stop in Waterloo where fleets and owner/operators were invited to compare the ride in identicallyspec’d trucks -one with traditional dualies and another with the X-One on the drive and trailer axles.

The improvement in stability was obvious, both visually and from inside the cab. An evasive maneuver routinely caused the trailer wheels to lift on the unit equipped with duals, while the tractor-trailer with the X-Ones barely swayed.

But while stability improvements are a nice bonus when using widebase tires, the real question on the minds of fleet managers and owner/ operators who attended the demo was how a switch to the fat tires would impact their bottom line.

According to Francois Beauchamp, special projects coordinator with Michelin,”The economic structure has changed over the last four years,” when Michelin first began promoting its X-One. He said a wholesale shift to wide-base tires in Canada could save the industry about 920 million litres of diesel per year.

“There used to be a tire budget and a fuel budget,” he added. “Now there’s only one budget there, and tires can become an integral part in saving fuel. We want our customers to make tires an integral part of their fuel strategy.”

Of the fuel consumed by a tractor-trailer as it moves down the road, 35% is a result of rolling resistance.

This is where tires can play a major role in affecting fuel economy. For every 3% reduction in rolling resistance, a 1% improvement in fuel mileage is achieved, Beauchamp explained.

Michelin says there are several factors that reduce the X-One’s rolling resistance compared to traditional duals. They include: tread depth; tread design; rubber compound; and casing architecture. With all those factors taken into the equation, Beauchamp said the X-One trailer and drive tires measure 73 and 92 respectively on the company’s Rolling Resistance Index, which uses the XZA-1+ as a benchmark. The lower the rolling resistance, the better the fuel mileage, and by comparison the XDA3 measured 115 and the XDA Energy measured 104, making the X-One more efficient than any other Michelin dual.

But while the fuel savings are difficult to dispute (especially in light of the well-documented Energotest conducted last year, an independent test which showed the X-One demonstrated a 9.7% fuel mileage improvement over duals), the real measure of value is total cost of ownership. Beauchamp admitted the X-One tends to have a slightly shorter life span than traditional duals. Even so, Beauchamp said when the fuel savings and reduced maintenance costs (fewer tires should result in less maintenance) are taken into account, a savings of $5,086 per truck can be achieved. Over a five-year lifecycle, that can amount to about $25,000 per truck, he noted.

The X-One can also result in higher payloads in some applications, he added, since converting from steel wheels and duals to aluminum rims with X-Ones can save 1,290 lbs if the steer, drive and trailer wheels are all converted. (You can save about 660 lbs if you’re already on aluminum wheels, Beauchamp pointed out).

A common concern about widebase singles is availability in the event of a blow-out. However, Beauchamp said Michelin is in the process of ensuring each of its dealers will have a ready supply of X-Ones available.

Other concerns involve reliability, but Beauchamp said fleets are experiencing fewer failures with the X-One, because it’s usually the oft-neglected inside tire on a set of duals that expires on the highway. And while it’s true that you can’t limp home if you blow a wide-base tire, Beauchamp countered that it’s a bad idea even on a set of duals as you risk damaging the casing on the remaining tires.

For more information on the potential benefits of wide-base singles, visit www. gowidesavegreen.com.

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