Achates Power has announced that its 10.6L three-cylinder opposed piston diesel engine—developed in a project funded by CARB—has entered fleet service with WalMart Corporation in California. The opposed piston power plant boasts decreased heat losses, lower pumping losses, and cleaner combustion than traditional over-the-road diesel engines, and is also the only diesel engine on the road capable of meeting CARB’s 2027 low NOx emission regulation. The engine makes use of a conventional underfloor DPF and SCR emission aftertreatment system, and notably doesn’t require a dual dosing SCR system to meet the coming NOx standards. The demonstration vehicle housing the Achates Power engine is a 579 model Peterbilt tractor.