John Deere Power Systems has developed solutions to meet the Interim Tier 4/Stage IIIB mobile off-highway emissions regulations for its lineup of industrial diesel engines. The regulations require at least a 90% reduction in particulate matter and up to 50% reduction in NOx from previous requirements. The firm will continue to offer its PowerTech displacements of 2.4, 4.5, 6.8, 9.0, and 13.5 L. Power ratings will also be similar to the Tier 3/Stage IIIA offerings. For its engines that are 56 kW (75 hp) and above, the company will start with its Tier 3/Stage IIIA PowerTech Plus engine platform, which includes cooled exhaust gas recirculation for NOx control, and add an exhaust filter for reducing particulates. Displacements in this power range include the 4.5-, 6.8-, 9.0-, and 13.5-L in-line four- and six-cylinder engines, all of which feature a four-valve cylinder head, high-pressure fuel system, turbocharging, and an air-to-air aftercooling system.