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Dec 6, 2012 12:37 PM

Meritor says it expects to offer a new  tandem axle, the “SMARTandem,” in 2013 that combines the benefits of 6x4 and  6x2 tandem designs into a 6x2 package that saves weight and helps boost overall  tractor fuel economy without skimping on performance.

  “We’re looking at a  variety of ways to boost drive axle efficiency and save fuel to help OEMs meet greenhouse  gas (GHG) regulations,” Charles Allen, Meritor’s general manager for rear  axle drives, explained during a press event at the company’s axle manufacturing  facility in Fletcher, North Carolina.

  Allen noted that  Meritor is in the midst of wrapping up two years worth of field tests with 15  customer trucks equipped with its new SMARTandem 6x2 axle configuration that he  believes successfully combines lighter weight and fuel savings of a traditional  6x2 setup with the performance characteristics of a traditional 6x4 design.

  “We’ve drawn features  from all our tandem axle models, especially the FUELite and 14X products, for  the SMARTandem design,” Allen said. “The SMARTandem offers about 400 pounds of  weight savings and a 2% improvement in fuel economy, but it also rated to  handle a GCVW [gross combination vehicle weight] of 110,000 lbs. and 2,050  ft.-lbs. of output torque. It also features automated traction control, load  shifting, and an automatic differential lock to give it traction equivalent to  a 6x4 model.”

  Matt Stevenson,  Meritor’s GM of North American field operations and marketing, told Fleet Owner that the SMARTandem also features  design influences from the company’s 17X rear tandem axle produced for the  European truck market and, when combined with wide-base tires on all wheel  positions, can save nearly another 400 lbs. in weight and boost tractor fuel  economy another 1% for a 3% overall improvement.  

  Stevenson noted,  however, that the 6x2 tandem axle configuration remains a relative rarity in  the North American truck market, with a survey of 500 customers conducted by  Meritor indicating that only 18.6% of those fleets operating more than 100  trucks equip them with 6x2 tandems, with only 16.3% of those operating 100 or  fewer trucks selecting the 6x2 model.

  “The objections to the  6x2 are typically over less traction, less resale value, and increased tire  wear,” he said. Yet the traction boosting technology added to the SMARTandem  along with adding as standard Meritor’s electronically-controlled air  suspension (ECAS) system to alleviate excessive tire wear should eliminate  those concerns, Stevenson believes.

  “The resale ‘penalty’  for a 6x2 versus a 6x4 tandem we’ve seen in our research is about $5,000; but  we think the fuel and weight savings offered by the SMARTandem could offset  that and more over a four year ownership period,” Stevenson said – noting that  the SMARTandem is currently “price neutral” in comparison with Meritor’s 14X  6x4 tandem product.

  “This should be a ‘no  sticker shock’ situation,” he stressed.

  “In our field tests,  which we’ve been conducting since November of last year, the trucks equipped  with the SMARTandem have been attaining 7.2 to 7.5 miles per gallon (mpg) – a  rough 2% boost to their baseline fuel economy,” Allen added. “In our  calculations, with diesel costing $3.80, the truck averaging 7 mpg over 100,000  annual miles, that 2% adds up to $1,064 in fuel cost savings per year.”

  Stevenson emphasized  that the SMARTandem won’t be an ideal fit for every fleet, as its best suited  for those operating on mostly flat stretches of roadway at highway speeds – not  mountain driving, for example, which is where the 6x4 configuration is ideal.

  “The point is though  that we’re simply running out of ‘low handing fruit’ in terms of how to achieve  fuel efficiency gains – and the impending implementation of GHG rules is  speeding up the demand for such gains,” he said. “That’s why we think that  while the 6x2 configuration only makes up 3% of the tandem axle market, it will  comprise 18% of the market within 5 years.”