Predictive cruise control, gap reducers score big on NACFE fuel efficiency study

Predictive cruise control was the fuel-saving technology with the most penetration in truck fleets by the end of 2018, according to an annual study by the North American Council for Freight Efficiency.

NACFE recently released its study of a select number of fleets both large and small and the technologies they are adopting — or not. NACFE studied 85 technologies and 21 fleets, with enough trucks to represent about 4% of the nation’s fleet. NACFE describes the study as a “deep dive,” resulting in the one-year timeline between the end of 2018 and the publication of the report.

While adoption of the technologies is not necessarily driven solely by a desire to increase fuel efficiency, it can be an impact from a fleet’s investment.

In the case of predictive cruise control, fuel efficiency is seen as one of its key benefits, according to at least one OEM. Kenworth said back in 2018 — when announcing that predictive cruise control would be standard on its T680 truck — that predictive cruise control “(combined) GPS with cruise control to deliver enhanced fuel economy.”

“The system uses topographical GPS data inputs to aid cruising speed efficiency. As the truck enters certain types of terrain, such as rolling hills, the system modulates cruising speed to optimize performance,” Kenworth said.

According to the NACFE data, 75.7% of the fleets it surveyed by the end of 2018 had predictive cruise control.

But the technology with the biggest growth in 2018 were tractor gap reducers. Gap reducers fill the space between the tractor and the trailer and reduce the wind drag that open space creates. 

According to the NACFE study, by the end of 2018, tractor gap reducers were only on 8.2% of the fleets surveyed. But that marked an increase of 1,839% from a year earlier. 

Source: NACFE

Another technology with huge uptake were FA-4 high-efficiency engine oils. In an information sheet published several years ago, Shell said FA-4 oils were “designed primarily for next-generation engines to help maximize fuel economy without sacrificing engine protection.” That would indicate that the increased penetration of FA-4 oils would be expected as old trucks are taken off the road to be replaced by new ones. The penetration at the end of 2018 for FA-4 oils was 31.6%, a jump of 531%, according to NACFE.

Another notable statistic: Tractor solar panels were on 6.4% of the surveyed fleets at the end of 2018. That was a jump of 126%.

Overall, the adoption rate for the technologies surveyed rose to 45% in 2018 from 17% in 2003. As NACFE notes, it can never get to 100%; some technologies are in conflict, with adoption of one foreclosing adoption of another.

But the study said there will always be numerous hurdles in getting fleets to adopt new technologies. “Multiple barriers have stymied industry adoption … including a lack of data about the true performance gains these technologies offer, and a lack of confidence in the payback for investment in these technologies.” NACFE seeks to overcome those barriers in part by publishing “Confidence Reports” on various technologies. It published one on idle reduction technologies last year.

The average annual rate of improvement in fleet miles per gallon in the study, going back 16 years, is 2%. But the increase to 2018 from 2017 for the fleets in the study did not meet that standard. It rose to 7.27 mpg from 7.23 mpg the year before. That’s an increase of about half a percentage point.

The study also has data on the fuel efficiency of the broader population of trucks, beyond those operated by the fleets studied. But it isn’t as up to date as the group in the study; NACFE reported that at the end of 2017, the broader fleet had an average of 5.98 mpg.

NACFE was able to get granular data from companies on how their 2018 model year vehicles operated. The organization did not share this data except on an aggregate basis. But NACFE did say the newer vehicles are generally operating at 7.5 to 9.5 mpg, and “some trucks were even found to deliver 10 mpg in certain routes, conditions and seasons.”

(The Run on Less demonstration in October 2019, testing what the NACFE said were “more demanding regional haul duty cycles, recorded an average of 8.3 mpg. A “best of the best” test in 2017 reached 10.1 mpg.)

Source: NACFE

One thing NACFE freely notes in its study: Fuel efficiency isn’t as big a deal for fleets as some other issues. The study refers to the annual study by ATRI, the research arm of the American Trucking Associations. That study lists the issues of biggest concern both to drivers and fleet owners.

The issue of fuel supply/fuel price was No. 1 in 2008 — not surprising since oil prices hit an all-time high in the middle of that year. But the issue of fuel price and supply hasn’t even been on the top 10 list since 2013, when it was No. 8. “Even if the adoption of technologies on their equipment increases or remains the same, a lack of focus on fuel economy and freight efficiency can have negative consequences,” the NACFE report said of the possibility of disinterest.

An issue that NACFE addresses is whether mpg is a fair measure of fuel efficiency. Why not use a ton-miles-per-gallon standard? The challenges in doing so for a study this wide are significant, the report said. “It is difficult to determine the actual loads in any given route, let alone day or year, and in some situations a load will cube out, the trailer fills with freight before reaching a maximum weight limit,” the NACFE report said. Given that, it is going to stick to mpg as its benchmark.