Fleets bemoaning the current cost of diesel fuel – and feeling pressure from customers' environmental, social and governance plans – already have a relief outlet with compressed natural gas (CNG).
Prices at the pump vary significantly across various states but, for the most part, a diesel gallon equivalent of CNG can be had for about half the cost. However, while offering a greenhouse gas emissions reduction of about 20% compared to a modern diesel engine, CNG is not a zero-emission solution.
The natural gas infrastructure is also not expansive by any measure. As of 2021, there were nearly 900 public CNG fueling stations in the U.S., according to the Department of Energy, but its footprint is fairly widespread except for a natural-gas no man's land in the Dakotas, Montana and most of Idaho.
By comparison, the DOE estimates there are roughly 55,000 Level 2 and DC Fast Charging EV stations coast-to-coast. While there is a massive cluster in California, the number of EV terminals across the rest of the U.S. is significant.
Peterbilt has been building medium-duty trucks for 27 years, and the company claims that 95% of that truck population is still in service. The company refreshed its medium-duty line about a year ago, but that process is ongoing. Peterbilt is phasing in a new hood design that aligns more closely with the brand identity found on its on-highway flagship models, adding a signature fender valley and dual-side air intakes – style features absent on prior medium-duty models.
Once my Model 536 rolled off the Peterbilt assembly line (equipped with the "old-style" hood), it was shuttled next door where it got its CNG upfit from Momentum. It still needed a 26-foot box, but I wasn't making any deliveries so I jumped in.
Momentum Fuel Technologies' upfit facility is next to Peterbilt's Denton, Texas assembly plant.Peterbilt offers two natural gas powertrain options in its medium-duty line: the Cummins B6.7N (as of March this year) and the L9N. My test truck was outfitted with the in-line six cylinder, spark-ignited, L9N for the horsepower bump. The B6.7N is rated for 200 to 240 horsepower and 520-560 pound-feet of torque, compared to the L9N's 250 to 320 hp and 660 to 1,000 lb.-ft. torque. My truck was spec'd to 300 hp at 2,100 RPM and 860 lb.-ft .torque at 1,300.
