MONTREAL, Que. — Performance Innovation Transport (PIT) has wrapped up testing on 6×2 tractors, which shows fuel savings of 2.6-3.5% compare to 6×4 configurations.

The testing was done in conjunction with PIT’s Energotest trials in Blainville, Que. in June. The testing also found 6x2s do have less traction than traditional 6x4s.

“The objective of our Energotest trials is to conduct controlled test-track studies for the trucking industry of technologies that increase fuel efficiency and lower emissions of greenhouse gas (GHG),” said Yves Provencher, director of PIT. “The results being released today scientifically demonstrate that for the vehicles tested, 6X2 tractors have better fuel performance than similar 6×4 tractors, which can lead to significant savings for fleets.”

The following vehicles were used for comparisons:

• 2013 Volvo VNL 64T 6×4 – Meritor MT40-14XC rear axle, 2.64 ratio
• 2014 Volvo VNL 62T 6×2 – Meritor RS23-160/161 rear axle, 2.67 ratio; Volvo non drive axle
• 2012 Kenworth T660 6×4 – Dana Spicer D40-170P rear axle, 3.21 ratio
• 2012 Kenworth T660 6×2 – 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 6×2-  Dana Spicer D40-170P rear axle, 3.21 ratio; modified (switched front and rear housing, emptied rear housing; gears not changed).

In tests using the SAE J1321 Fuel Consumption Test Procedure – Type II (SAE International 2012) for Kenworth models, 6×2 tractors consumed from 2.6% to 3.5% less fuel than similar 6×4 models. Using the TMC-SAE Type III Test Procedure (SAE J1526), the Volvo 6×2 tractor used 3.3% less fuel than the 6×4 model.

PIT traction performance evaluations of the 6×2 and 6×4 tractors used a pull sled test to compare pulling distance, maximum speed and acceleration. When pulling the same sled on a similar surface, the 6×2 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 6×4 tractors.

PIT will host its next biannual Energotest at the Transport Canada test track from Sept. 11-19. The event will feature fuel consumption tests comparing North American and European trucks in addition to testing the fuel consumption claims of many new products on the market.