Study says 6×2 axles average 2.5 percent better fuel mileage

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Find out more about the North American Council for Freight Efficiency via nacfe.org.Find out more about the North American Council for Freight Efficiency via nacfe.org.

In collaboration with the Carbon War Room initiative, the North American Council for Freight Efficiency announced results of a study of existing literature on, as well as new track tests of, 6×2 tractor axle configurations and fuel efficiency versus that achieved with more common 6×4 set-ups. Tests examined and performed showed a range of increased efficiency, from as little as 1.6 percent to as much as 4.6 percent — NACFE concluded an average 2.5 percent could be expected for many fleets with a conversion to a 6×2 configuration. 

Kevin Rutherford, writing as part of the Dollars and Sense column in Overdrive in April last year, noted he rarely recommended conversion to 6x2s to owner-operators given the long payback time with a cited 5 percent boost in fuel mileage. The NACFE report, however, notes that owners “can be confident that they will enjoy about a 2.5% reduction in fuel use, and payback on investment in about 20 months, by adopting currently available 6×2 axle technologies.”

The 6×2 “confidence report” in NACFE’s Trucking Efficiency series follows reports on speed limiting technologies for fleets and wide-single tires — in the latter case, 3 to 6 percent greater fuel efficiency was cited as a reliable estimate for operations where singles were a possibility. 

Report authors hoped results would “catalyze significant new interest in the 6×2 axle technology as a way to increase fuel efficiency and obtain other benefits.”

Some particulars of the analysis and tests in the 6×2 report can be found in the chart below. Download the summary report via this link. 

Find more about the report via nacfe.org. 

Click through the image for a larger version of the chart. Download the summary report on 6×2 axle adoption via this link.Click through the image for a larger version of the chart. Download the summary report on 6×2 axle adoption via this link.