Kohler Engines, along with Italy-based Lombardini, present the 1.9-liter KDI1903TCR and 2.5-liter KDI2504TCR heavy-duty diesels. The engines meet Tier 4 Final emissions without the use of a diesel particulate filter, thanks to efficient use of components, including Kohler’s direct injection system, cooled exhaust gas recirculation and diesel oxygenated catalyst. The high-pressure common rail system utilizes pressures at 29,000 psi. The KDI1903TCR produces 56 hp at 2,600 rpm and 166 ft.-lbs. of torque at 1,500 rpm, and the KDI2504TCR offers 74.3 hp at 2,600 rpm and 221.3 ft.-lbs. of torque. Other features include less noise and vibration, as well as a heavy-duty crankcase for increased durability.