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6x2s and how your government is putting you at a competitive disadvantage

New-generation 6x2 axle configurations reduce weight, save fuel and cut emissions. What’s not to like?

TORONTO, Ont. — Six-by-two axle configurations – in which only one of the two drive axles provides power to the vehicle – are gaining a lot of attention for their weight- and fuel-saving potential.

According to Meritor, one of several manufacturers to produce 6×2 axles, about 4-5% of the North American Class 8 truck build for 80,000-lb GCW on-highway applications is currently being ordered in such a manner.

“We think it’s going to hit 16% within the next four years,” John Nelligan, general manager, sales and marketing, Meritor North America, told Truck News.

The advantages are obvious. Six-by-twos reduce weight by about 400 lbs, which can be converted into payload or translated into a fuel economy improvement ranging from 2.5-6%. And it’s not just the manufacturers citing these numbers. A recent study by the North American Council for Freight Efficiency (NACFE) looked at real-world usage as well as on-track tests and found that 6x2s delivered fuel savings averaging 2.5%. The results were even more impressive when singling out carriers using 6x2s in real-world applications, where average savings amounted to 3.5%.

The environmental benefits are staggering. A 6×2 truck averaging 120,000 miles per year at 6.5 mpg that reduces its fuel consumption by 3.5% would reduce its CO2 output by 14,592 lbs each year. And that’s just one truck.

But unfortunately, Canadian carriers looking to enjoy these savings – and Canadians who wish to breathe cleaner air – are being denied the opportunity by legislators in this country. Ironically, a Memorandum of Understanding that was intended to harmonize weights and dimensions regulations across the country – to effectively reduce red tape for carriers – may be partly to blame.


When is a tandem not a tandem?

The MOU defines a tandem axle as a dual axle assembly in which weight is distributed evenly across both axles at all times. While this is almost always the case with today’s ‘smart’ 6x2s with electronic load-shift capability, there are times during low-traction events in which the weight is shifted temporarily to the driven axle to improve grip. These electronic load-shift systems, such as Meritor Wabco’s Electronically-Controlled Air Suspension (ECAS), address long-running concerns about traction in 6×2 configurations and make 6x2s viable in wintery or hilly geographies. But they also, in the eyes of some Ontario bureaucrats, effectively transform the non-driven axle into a liftable axle – even when the axle does not, in fact, lift.

Make sense? We didn’t think so. So we asked the MTO, via a spokesperson, for an explanation of the rules. We got back government gobbledegook (see Appendix A).

We then turned to Meritor, which along with industry partners has been lobbying provincial and territorial governments to allow the use of current generation 6x2s. Meritor’s Brad Hicks has been involved in the discussions.

“Here’s the issue,” he explained. “The way they define a tandem axle is: two closely coupled axles, neither of which is liftable. But then when they further interpret the definition of liftable axle, they are taking the position that any axle whose loads can be modified – either by the driver or even automatically – is considered a liftable axle. We’ve tried to make the argument that you never completely unload the non-driving axle, or tag axle, during load transfer but they have taken the position that by their definition, it is liftable and therefore is not an approved tandem axle configuration for SPIF vehicles.”

Those same ground rules don’t apply for non-SPIF vehicles, but those are limited to trailer lengths of 48 feet.

All the provinces and territories but B.C., Quebec and Ontario have indicated a willingness to rewrite the MOU to clarify the rules and to pave the way for the allowance of modern 6x2s, Hicks said. B.C. has taken a firm stand against 6x2s over fears traction will not be sufficient given the province’s mountainous terrain. That position is not likely to change, so B.C. fleets can rule out 6x2s for the foreseeable future. (There are drivers in Europe – where 6x2s are mainstream and where some significant mountain ranges reside – who may think concerns about traction are overstated. But that’s an argument for another time).

The greatest frustration in all of this is that Ontario and Quebec are digging in their heels when there seems to be no reasonable technical reason to prohibit 6x2s. In doing so, they’re depriving their respective provinces’ trucking companies the ability to compete with US carriers that can use 6x2s unfettered right across the country and who undoubtedly run those same trucks north of the 49th parallel.


A competitive disadvantage

While not much has been made of this issue at the fleet level, Truck News has spoken to carriers that are running 6x2s in Canada knowing they’re technically illegal.

“There’s no way for MTO to actually catch one redistributing weight, unless they were to put a couple hundred feet of glare ice on the approach to the scale platform,” one fleet manager told Truck News, admitting he was willing to take the chance.

Rob Penner, COO and executive vice-president of Bison Transport, expressed frustration that lawmakers in Canada are keeping his company from using technologies that are widely used by US competitors.

“We continue to be extremely frustrated by regulations that prohibit the effective use of new technologies, particularly those designed to reduce the cost of fuel consumption and the reduction of tractor weight,” Penner told Truck News. “The feds and provinces speak out of both sides of their mouths when it comes to environmental regulations and business policies.”

He noted the federal and provincial governments have had no problem adopting emissions standards that forced the use of unproven technologies, burdening the industry with excessive downtime and related costs. Ontario also is pushing forward a mandate that will require the use of biofuel, which is known to pose problems in cold weather.

“Yet, when it comes to industry-led initiatives that present tried and true fuel economy improvement strategies, which also benefit the environment in a meaningful way…we have to battle for years just to be heard.”

The end result, said Penner, is that “We are left at a competitive disadvantage to our American counterparts, who are continuously citing remarkable fuel economy gains with the added use of these technologies. They are utilizing this enormous cost-based advantage to sell against us on cross-border business and worse yet, you don’t have to look very hard to see them running within our national and provincial boundaries with the very same equipment we are not allowed to legally operate.”

Meritor’s Nelligan acknowledged some Canadian fleets have conducted a cost-benefit analysis and have decided it was worth the risk to run 6x2s in Canada.

“I would venture to guess that if you went to a scale and looked underneath a few trucks, you’d find a few of them are missing interaxle drivelines,” Nelligan said. “There are some in Canada. We don’t want to start a witch-hunt but we do have fleets trying them. A lot of these fleets are running a very high percentage of their time in the US and they have to compete with US fleets, so they need those same advantages those US fleets have in fuel economy and weight.”

While Meritor stops short of recommending 6×2 axles with ECAS in Canada, truck dealers here are more than willing to take orders for them. The load-shift capabilities are enabled only in low-traction situations and at 25 mph, weight is automatically redistributed across the two axles. About 97% of the time, a 6×2 axle with ECAS meets the legal definition of a tandem axle. Adding to the confusion, a 6×2 without load-shift capabilities is not illegal – but it is impractical. But it would be difficult, if not impossible, for a truck inspector to differentiate between a traditional 6×2 and one with electronic load-shifting capabilities.

“What are the odds that trucks are going to go over the weigh scale in load-transfer mode? Those odds are pretty low,” Hicks said. “Some unnamed provinces and territories have said, ‘why worry?’ We can’t in good conscience promote the use of a product that’s violating the regulations but as a practical matter, I’m guessing there’s some (6×2) US trucks that have travelled into Canada – trucks that are perfectly legal in the US – and they’re not being detected.”

Hicks repeated that even in Ontario and Quebec, from whence most resistance has come, policymakers have acknowledged the benefits of 6x2s. But they indicated the challenges in changing the existing rules are too burdensome to overcome.

“Everyone has been pretty supportive of the concept,” Hicks said. “In Ontario, they have said to make a change like this, it has to be a legislative change and that is very, very difficult for them to make and they are not prepared to do so. Nobody has said this is not a good idea. They can see the merits of it. But there are a couple provinces that can’t see a way forward given the laws that are on the books currently.”

Of course, legislation can be – and has been – changed, especially when the environment stands to benefit (ahem, speed limiters). Nelligan is hopeful carriers looking to achieve the same benefits as their American counterparts will bring this issue up with their elected representatives and their trade associations.

In the meantime, Meritor – along with partner organizations and even competitors – continues its lobbying efforts. The Task Force on Interprovincial Weights and Dimension Policy has developed a recommendation that would allow ‘smart’ 6x2s, by permitting temporary load-shifting from the tag axle onto the drive axle of advanced 6×2 systems. Eleven of the 13 provinces and territories supported the proposed change.

That proposal was forwarded to the Deputy Ministers of Transportation and Highway Safety for approval in April but they did not approve the change. That group will reconvene in September, at which time Meritor hopes it will be successful in influencing change. One possible outcome is that some provinces will adopt the change while others will not – meaning it’s possible that Ontario and Quebec could continue to prohibit the use of smart 6x2s while the other provinces, which have sh own support, will allow them.

The arguments in favour of allowing smart 6x2s are simply too strong to abandon, or to ignore, Hicks reasoned, adding that even when in full load-shift mode, the driven axle never exceeds the allowable single axle limits in any province or territory.

“It almost gets down to a situation where the provinces and territories are victim of this well-intentioned requirement (in the MOU) that the loading be equal,” he said.

If action isn’t taken to amend the legislation, Nelligan suspects Canadian carriers will force the issue further as 6x2s become more mainstream in neighbouring jurisdictions.

“When you’re talking about 2.5%, 2.9%, that’s an awful lot of money per truck, per year,” Nelligan said. “I think it’s something where, if you’re a major Canadian fleet that runs north-south and you don’t have the advantage of having these products, it’s going to be something you’ll want to get vocal about.”

At least one fleet manager Truck News spoke to, the one mentioned above who isn’t waiting for government to approve the use of 6x2s, isn’t afraid to get vocal.

“It is sad the MTO is so archaic,” he said, asking not to be identified for fear of becoming an enforcement target. “Bureaucratic BS is really all it amounts to. As for me, I intend to purchase the 6×2 (in quantity) and will gladly take my chances in a court of law (if fined).”



Appendix A: We asked the MTO simply whether or not 6×2 axle configurations are legal in Ontario. This is their explanation:


6×2 tractor axle configurations are allowed in Ontario, however they must meet definitions as set-out in Regulation 413/05 in the Highway Traffic Act (HTA). There are some ‘smart’ 6X2 tractor axle configurations coming to market that do not meet the definition of dual axle and tandem axle in Ontario. ‘Smart’ 6X2 tractor axle configuration systems are not legal in Ontario because they do not load equalize at all times and can be considered liftable axles.

Tractors in Ontario are defined as being equipped with fifth wheels. The front axle of the tractor is a single axle with single tires, and drive axle of the tractor is either a single or tandem axle.

Within Regulation 413/05 we define:

“drive axle” means an axle unit that is connected to the power source of a motor vehicle and that transmits tractive power to the wheels;

“tandem axle” means a dual axle as defined in section 114 of the Act that does not include a liftable axle or a self-steering axle and that has the same number of tires at each wheel position;

The HTA defines:

“Dual axle” means any two consecutive axles whose centres are more than one metre apart and that,
(a) are articulated from a common attachment to the vehicle, or
(b) are designed to automatically equalize the load between the two axles. [HTA s114]



James Menzies

James Menzies

James Menzies is editor of Truck News magazine. He has been covering the Canadian trucking industry for more than 15 years and holds a CDL. Reach him at or follow him on Twitter at @JamesMenzies.
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6 Comments » for 6x2s and how your government is putting you at a competitive disadvantage
  1. Michael Ludwig says:

    Fortunately for Ontarians, this is an election year. Let’s get this issue out in front of the candidates right away and get some sort of election commitment. Fourteen thousand pounds of reduced carbon emissions, per truck, is hard to ignore.

  2. Tom MacKay says:

    MTO’S stand is typical of their lack of foresight and understanding of the trucking industry and how trucks are built. I am quoting on an ECAS training simulator for an American school which has a desire to train technicians on how ECAS works and how to diagnose problems with the system should they arise. Technical schools in the U.S. would not be purchasing a trainer if this technology was not mainstream. MTO’S position on ECAS is confusing as highway coaches have used a similar system for years on the tandem axle configuration on these large buses.

    MTO allows lift axles on dump trucks which beat the road up when the axle is lifted to turn corners yet will not allow ECAS. How narrow minded and uninformed they are! When new technologies can save money and the environment, without costing the trucking industry tons of money, legislators stand in the way. But lets legislate biodiesel and cause truckers problems and lots of money.

  3. Angelo says:

    In the mid 80s, I drove a tandem straight truck with an air lift tag axle ( 26 ft box) . The truck only needed a 210 hp DT466 to do the job. I never got stuck in winter as I could manipulate the axle up to 85 psi which got me out of an over weight fine in Virginia. Very nice set-up. Merritors modern 6×2 removes the human factor for error- what’s not to like? Perhaps the fuel savings when implemented on a large scale would see a depletion of their fuel tax revenue? This type of forward thinking is already in use world wide. This is real fuel saving technology.

  4. Rob says:

    I used to think it was our elected officials who seem to be the root cause, and that the governments they operate within are so bureaucratic that changing law is next to impossible… but then I see things like speed limiters, environmental initiatives and tax law (see MB and how they attacked NatGas before any fleets even adopted it) virtually changed over night. So we know changing the law isn’t the hard part… I think it’s more about motive and incentive… Feels to me like the Regulators and Enforcement are highly motivated to wield a stick or reach into our wallet, but have absolutely no motivation to do something to actually try and help. If they wanted to help, they’d get behind usthis changed, not just sit back and cite all the difficulties that lie within current guidelines.

    Also, it truly is disappointing to hear fleets are simply taking their chances on operating technology that is deemed “illegal or non compliant.” I can say for sure we have been tempted, but I have not been able to find a way to tell our drivers that they must follow all the laws and regulations that pertain to them as individuals, but never mind the ones that pertain to my responsibility in putting a compliant spec on the road… The law is the law…

  5. Rob Barnett says:

    When did we get “13 provinces” ?

  6. Bill Dawson says:

    It’s time to take the technology to key representatives at MOU, with a strong contingent of Canadian Carriers in tow , who employ tens of thousands of Canadians . MOU personnel need to experience the handling , and performance dynamics , in a real world comparison of SMART 6×2 , versus the traditional 6×4. The smart 6×2 is a dramatic breakthrough , which cannot be shackled by tradition and lack of forward thinking !

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