Electrification gets most of the buzz around new truck engines. But Japan’s Isuzu Motors Ltd. and Cummins Inc. want to focus on diesel engines and make less-polluting models together.
“ ‘Don’t write diesel off yet’ seems to be the message here,” said Antti Lindstrom, a trucking analyst with IHS Markit.
New federal rules taking effect in 2021 will cut greenhouse gas-trapping nitrous oxide emissions. Meanwhile, California toughens regulations in 2023. The state also wants trucks to be emission-free by 2035.
Isuzu makes seven series of industrial diesel engines. The top one is a 15.7-liter model that produces up to 512 horsepower. Those engines do duty in Isuzu’s medium-duty trucks, fork trucks, air compressors, generators and other equipment. The company doesn’t use Cummins engines.
“This partnership is a terrific opportunity to leverage our strengths and create new opportunities to grow the product portfolio,” said Tom Linebarger, Cummins’ chief executive.
That partnership includes an alliance board and a team to explore technology, sourcing and manufacturing. The board reinforces diesel power even as Cummins devotes more resources to electrification.
Diesel should remain the main technology for commercial trucking for the next 10-15 years and beyond, according to the Diesel Technology Forum.
A nationwide network of diesel fuel stations is in place. Other advantages of diesel engines over rival powertrains include their being energy-efficient, power-dense and reliable, said Allen Schaeffer, the forum’s executive director.
“We’re confident diesel’s proven strengths will be challenging to beat,” he said.
Diesel fuels the majority of medium- and heavy-duty trucks. Big trucks account for 4 percent of U.S. highway vehicles and about 10 percent of miles traveled. Yet, according to the U.S. Environmental Protection Agency, they generated about 23 percent of greenhouse gas emissions from transportation in 2016. That’s the latest year for which data are available.
Diesel engines are getting cleaner. That’s because manufacturers now use ultralow sulfur fuel, high-pressure fuel injection, particulate filters and diesel exhaust fluid in pollutant-trapping selective catalytic-reduction systems.
IHS Markit found that 36 percent of 2017 model-year medium- and heavy-duty trucks use the newest generation of clean diesel engines.
“Isuzu and Cummins recognize the advanced diesel engine will continue to be an important power choice for global customers,” said Masanori Katayama, Isuzu president. And both developed and emerging countries feel that way, he added.