Net-zero emissions is the name of the game, at least that’s the ideal that most engine manufacturers hope to achieve at some point by the middle of this century. For now, they’re all making incremental improvements to ensure that their systems run cleaner, greener and leaner.

The following are a number of updates on the engine efficiency front:


In February, Cummins announced that it is launching what it calls the industry’s first unified, fuel-agnostic internal combustion powertrain solutions, using engine blocks and core components that share common architectures and will be optimized for different low-carbon fuel types. The new platforms will feature a range of engine versions that are derived from a common base engine — ensuring that they will be able to use many common parts. The commonality of parts will enhance benefits for OEMs and end users, allowing for similar engine footprints, diagnoses and service intervals.

The area below the engine’s head casket largely will have similar components, while the area above the head gasket will have different components for different fuel types. Each engine will operate using a different, single fuel. The new design will be applied across the company’s B, L and X-series engines, available for diesel, natural gas and hydrogen. 

Designed as an integral part of Cummins’s strategy to “go further, faster,” the new offerings will reduce the greenhouse gas and air quality impacts of its engines.

That dovetails with the company’s recent announcement that it is collaborating with Isuzu on a battery electric solution. Through that arrangement, Cummins will integrate its PowerDrive6000 into Isuzu’s F-Series and will pilot the truck with some prominent North American fleets later this year.  


In other Cummins-related news, Daimler last year established a global strategic partnership for medium-duty engine systems. Under the terms of the agreement, Cummins has agreed to invest in the further development of medium-duty systems for Daimler Trucks, with production and delivery of those engines beginning in the second half of the decade. Cummins is building a new engine plant within the Mercedes-Benz Mannheim campus.

Daimler says it anticipates that the Cummins partnership will enable it to increase and accelerate development of alternative and emerging technologies, including non-diesel engines. The company notes that in the future it will focus on the further progression of zero-emission technology, as well as the further development of commercial heavy-duty drivetrains.


Navistar recently announced major updates to the International A26 engine, noting that fleets now will be able to realize 10% improved fuel economy since the engine’s first launch.

Prior updates resulted in a 6% fuel efficiency improvement, while the latest enhancements provide an additional 4% of cost savings.

Those updates include an increased compression ratio from 18.5:1 to 20.5:1, which delivers higher combustion efficiency; optimized engine temperature control; improvements to the air management system and a reduced engine speed without compromising power.


PACCAR says its 6.7-liter PX-7 engine offers superior performance, while minimizing operational costs and maximizing uptime for medium-duty vehicles. That means reduced maintenance, long service intervals and optimal fuel efficiency across the life of the truck. The PX-7 is available in horsepower ratings from 200 to 360 horsepower and offers up to 800-pound-feet of torque.

Meanwhile, PACCAR says that its 8.9-liter PX-9 engine has one of the highest power-to-weight ratios in its class and will move heavy payloads “without hesitation.” It’s available in both medium- and heavy-duty configurations.