Commentary: Don’t count out diesel just yet

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At the North American Council for Freight Efficiency (NACFE), we believe that electric trucks are the technology that will dominate the future. However, that does not mean we think diesel trucks are going to disappear overnight.

Rick Mihelic is the director of Future Technology Studies for the North American Council for Freight Efficiency (NACFE)Rick Mihelic is the director of Future Technology Studies for the North American Council for Freight Efficiency (NACFE)

All technology adoption tends to follow an S-curve pattern. Technology S-curves are real, whether discussing the stereotypical growth of market penetration from the fledgling market entry to near market dominance with mature product or talking about the potential for technology improvement as products mature. S-curve behavior applies to performance, reliability, life span, economy and other factors.

Singular major transportation technology shifts occur less frequently than do a collections of incremental annual broad-spectrum technology improvements, but they do occur. An example previously reported by NACFE is called “dieselization,” which occurred between 1938 and 1965 with the introduction – and rapid adoption – of the diesel-electric power systems for trains that replaced steam power systems.

Each of the alternative energy technologies rolling out for trucking will have its own technology S-curves as the market decides where investment makes sense, as the products mature and as parallel innovations arise to compete with or help them mature. The speed at which each technology advances will depend on market demand, which fuels investment in research and development.

However, diesel technology, while on the mature market dominant end of the S-curve, will not stop seeing improvements. Yes, the improvements will be more incremental, but they will be spurred either by regulatory changes or the desire of diesel engine manufacturers to continue to provide fuel efficient options for fleets. This also brings up a nuance to the adoption curves in that each market segment has its own path to scaling.

Another reason that diesel will be around for some time is that the business case for electric vehicles has not been proven for all applications. To be clear, there are applications today where commercial battery electric vehicles (CBEV) offer a nice pay back: like transit and school buses, medium-duty trucks and segments of  regional haul tractors. But the widespread adoption of CBEVs in long-haul trucking is a little farther into the future.

Fleet trade cycles vary widely, and that will influence how quickly a new technology reaches widespread adoption. Some fleets trade their trucks after only three years, while others hang on to them for 12 or more. During a fleet panel at the recent Heavy Duty Aftermarket Dialogue, Scott Reed, senior vice president of fleet purchasing & maintenance at Werner Enterprise, said Werner sells its trucks with under 400,000 miles on the odometer. On that same panel, Bob Phipps, maintenance supervisor art Bettendorf Trucking, said, “We keep our tucks forever,” adding that he has trucks in the fleet that have four million miles on them.

Regardless of how quickly CBEV technology progresses, rest assured diesel trucks will be on the roads for years to come. As I said at the beginning, NACFE believes the future is electric, but there will be many diesel trucks on the road — as well as those with other powertrain options — until we get to that day.

Rick Mihelic is NACFE’s Director of Future Technology Studies and President of Mihelic Vehicle Consulting LLC. He has authored Guidance Reports on electric medium- and heavy-duty trucks, thought leadership papers on regional haul and defining production and Confidence Reports on determining efficiency, tractor aerodynamics, trailer aerodynamics, two truck platooning.