Among the many fuel-saving strategies you might employ, spec’ing the new generation of wide single tires is one of the most effective ways to make a good dent on your part of our environmental footprint.

Put your fuel bill on a diet, to the tune of at least four percent, and you’ll reap big rewards by making both your bank manager and David Suzuki smile at the same time.

“At least four percent” is the fuel-saving claim that Michelin makes for its wide single tires when used on both tractor and trailer in a typical 80,000-lb U.S. spec. Bridgestone, the other key player in the singles game, says you’ll save between two and five percent in linehaul work.

Goodyear, by the way, is not marketing wide singles at present. To clarify Goodyear’s position, marketing communications manager Tim Miller says they do in fact sell wide singles for both drive and trailer positions here in North America, but the tires are European and imported — mostly for Schneider National — on a special-order basis only.

Turning 18-wheelers into 10-wheelers sounds wrong but fuel gains mean you would save somewhere between $2,500 and $3,000 on each rig annually. With just 50 of them in your yard, that’s at least $125,000. Even after taxes, there’s your new Harley, and the rest you can use to fund the first three months of your kid’s university career. Those figures assume, for ease of calculation, 100,000 miles in a year, 6.5 mpg, diesel at 95 cents a liter, and a four-percent reduction in fuel used.

So why are wide singles going to save fuel? It’s about rolling resistance, and singles drop that by about 12 percent. Mostly it’s because you’ve only got half as many sidewalls flexing, which creates heat and wastes energy.
But the advantage goes further, because you’ll spend less to buy singles and the appropriate wheels in the first place, though retrofitting doesn’t make financial sense.

You’ll save weight as well, and if you can actually exploit that extra payload potential, you can thus put a little more money aside to educate the kid. The saving, depending on whether you’re comparing steel wheels or aluminum, will be somewhere between 750 and 1,350 lb, says Michelin.

Miller, an engineer and former tire designer turned marketer, says this is a better reason to make the switch than fuel economy. His point is that you could make similar gains using fuel-efficient conventional tires without the potential complications.

Nonetheless, another advantage to wide singles is the ease with which the air pressure or general condition of four tires on a tandem axle can be checked by a driver or mechanic. Given that most tire failures occur on the tough-to-check inner dual tire, the gain here should be real.

Wide single tires save fuel and provide a
superior ride and more precise handling.

In the shop, mounting and de­mounting is no different, and singles fit into your cages. But they’re heavy, 50 lb or so more than a conventional 11R22.5 drive tire, for example. This means you may have to provide your tire guys with some mechanical means to lift these things.

Speaking of maintenance, one of the perceived downsides to wide singles is that they’ll cause you woe if they fail on the road. True enough, if you need a replacement in Timbuctu, you may have an issue.

“Most of the questions we receive from truckers considering X One wide single tires are related to flats and availability,” says Michelin’s Michael Burroughes. “We’ve actually had a lower instance of flats and in the unlikely event it does happen, we have set up a toll-free number to get a replacement tire for the vehicle as soon as possible.”

While the poster-boy fleet for successful use of wide singles in Canada is Danfreight of Joliette, Que., another pioneer is an Ontario owner-operator.
Wayne Robertson of Kitchener has had 455/55R22.5 Michelin X One tires on his 2002 Peterbilt 379 since 2004. He pulls a 48-ft stepdeck and runs the Toronto/Texas corridor with 75,000-lb loads.

“I have experienced excellent traction and stability with these tires, and my fuel economy has improved by at least one half mile per gallon,” he says.
“My tires will soon need to be replaced but I have about 450,000 km on them,” he says, “and would have gone further if I had recognized early on that I didn’t have enough pressure to keep the tires wearing evenly across the face.”

Robertson’s happy experience points to the importance of proper maintenance in general, pressure in particular, and the jury’s still out on whether singles need more careful care.

Other single advantages, and anecdotal driver reports confirm them, include quieter running, a superior ride, and better, more precise handling.
But can you use them in Canada? Well, there’s been progress with provincial regulators and weight allowances, but there remains a barrier promoted by pavement engineers who confuse the new generation of singles with the older versions often called ‘super singles’ or ‘flotation’ tires. The latter did indeed damage pavement, but several studies have shown that the current breed of singles do not. Or if they do, the effect is minor.

Manitoba recently announced it would allow singles 7,700 kg (16,975 lb) per axle, as B.C. did a while ago. Nova Scotia just announced the same weight allowance and New Brunswick is expected to follow suit. At those weight thresholds, single tires are mostly economical for U.S.-bound loads, where the 17,000 kg maximum (7,700 kg per axle) is at par. Ontario allows 8,000 kg (17,367 lb), but only Quebec gives the full 9,000 kg (19,841 lb) enjoyed by dual tire sets (by permit only).

All other provinces and territories are still stuck with the rule that says no single tire can carry more than 3,000 kg (6,614 lb) or 6,000 kg per axle.

Are wide singles for everyone, anyway? Clearly not. They’re best for folks with kids in college.