NASHVILLE — Over 41,000 tractors and 125,000 trailers were surveyed for what is being dubbed as one of the most comprehensive studies of class 8 fuel efficiency adoption ever conducted.

The study was done by the North American Council for Freight Efficiency (NACFE), a non-profit organization, that wanted to examine the fuel saving technology — fuel saving technology that works, that is.

The scope of the study included 10 fleets — Bison and Challenger among them — and included regional and long-haul tractors and trailers in dry goods and refrigerated cargo movement. All the tests are done in the "real world" which gives "real results," NCAFE said.

The fleets surveyed saved on average $5,700 per year or $22,800 over four years in fuel expense. Compared to 2011's study, that's an increase of $1,300 per truck per year change, NACFE said.

The study also analyzed the adoption of 60 known technologies and practices available to fleets over the past eight years. The study found that the average purchased adoption rate of the products increased from 31 percent to 50 percent between 2003 and 2012. Average fuel economy performance of the trucks improved 0.53 mpg against a "business as usual prediction for emissions technologies and very limited adoption."

Operating practices like speed limiting, routing software and driver training were universally adopted at 90 percent, said NACFE.

The products that made the most dramatic improvements? Tires and wheels including wide-based tires, low rolling resistance duals, aluminum wheels and tire inflation and monitoring systems.

The study is available for purchase — "We're a non-profit," explained Mike Roeth, Executive Director of NACFE, who stressed the organization's unbiased approach during a press conference at the Technology and Maintenance Council on Sunday.

But there's bang for the buck, according to Scott Perry, vice president of Vehicle Supply Management, Ryder Management. "We saw immediate value in quality data about what other good companies are doing," he said. “That in turn will benefit everyone, because when manufacturers have more confidence about the market for their solutions, they can make investments that bring down costs. We can also have more informed conversations with regulators and take a more focused approach to influencing public policy in areas such as alternative fuels.”

Roeth said that the organization would like to be a "Consumer Reports" for the trucking industry, providing informative, practical data on products. The full report is available here. 

In the meantime, here are the Top Five Fastest Adopted Products:

1.Trailer skirts

2.Idle shutdown

3.Tractor chassis skirts

4.Low rolling resistance duals

5.Geardown protection