FPInnovations’ Performance Innovation Transport (PIT) group, a not-for-profit engineering and research center for the North American trucking industry, compared 6x2 and 6x4 trucks during the PIT Energotest trials that took place earlier this year at the Transport Canada Motor Vehicle Test Centre in Blainville, Quebec.
The test results showed that 6x2 tractors consume less fuel than similar 6x4 tractors. However, 6x2 tractors showed reduced traction in comparison to 6x4 models.
“The objective of our Energotest trials was to conduct controlled test-track studies for the trucking industry of technologies that increase fuel efficiency and lower emissions of greenhouse gases (GHG),” said Yves Provencher, director of PIT. “The test results scientifically demonstrate that for the vehicles tested, 6X2 tractors have better fuel performance than similar 6x4 tractors, which can lead to significant savings for fleets.”
In the evaluations of fuel consumption and traction performance of 6x2 and 6x4 tractors, PIT compared the following vehicles:
• 2013 Volvo VNL 64T 6x4—Meritor MT40-14XC rear axle, 2.64 ratio
• 2014 Volvo VNL 62T 6x2—Meritor RS23-160/161 rear axle, 2.67 ratio; Volvo non drive axle
• 2012 Kenworth T660 6x4—Dana Spicer D40-170P rear axle, 3.21 ratio
• 2012 Kenworth T660 6x2—Dana Spicer D40-170P rear axle, 3.21 ratio; modified (emptied rear housing, removed the drive shaft between front and rear housing, change gears in the front housing, same ratio)
• 2012 Kenworth T660 6x2—Dana Spicer D40-170P rear axle, 3.21 ratio; modified (switched front and rear housing, emptied rear housing; gears not changed)
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In tests using the SAE J1321 Fuel Consumption Test Procedure-Type II (SAE International 2012) for Kenworth models, 6x2 tractors consumed from 2.6 percent to 3.5% less fuel than similar 6x4 models. Using the TMC-SAE Type III Test Procedure (SAE J1526), the Volvo 6x2 tractor used 3.3% less fuel than the 6x4 model.
PIT traction performance evaluations of the 6x2 and 6x4 tractors used a pull sled test to compare pulling distance, maximum speed and acceleration. When pulling the same sled on a similar surface, the 6x2 tractors traveled from 5.4% to 13.5% shorter distances, reached maximum speeds that were about 17% lower, and exhibited from 10.5% to 35% slower acceleration rates compared to the 6x4 tractors. This test was a first field cooperation with the NACFE and PIT wishes to thank the group for its participation.
For more details on the methodology, truck configurations or results of this study, please contact PIT.
Formed in 2008, PIT works in cooperation with the US SmartWay Transport Partnership, Natural Resources Canada, and Environment Canada PIT evaluates and implements technologies that promote efficient energy use in the commercial transportation, municipal and transit industries and has grown to include 26 fleets, 16 municipalities and four federal and provincial government agencies.
For more information about PIT, visit pit.fpinnovations.ca. For more information about FPInnovations, visit: www.fpinnovations.ca. ♦