Caterpillar Inc.'s C9 Advanced Combustion Emission Reduction Technology (ACERT) engine for heavy-duty trucks has received certification by EPA. The C9 engine is popular with customers who operate emergency and recreational vehicles, mass transit buses, and vocational trucks such as refuse haulers and dump trucks, Cat said. Full production of the C9 will begin in the first quarter of this year. Cat said the technology provides a long-term emissions solution for the North American trucking, bus, construction and mining industries, and positions Caterpillar to meet future EPA emissions regulations for both on and off-highway engines. Engine makers can sell only heavy-duty truck diesel engines that meet the new EPA emissions standards: 2.5-grams oxides of nitrogen (NOx) plus non-methane hydrocarbon (NMHC). While most engine makers are using cooled exhaust gas recirculation (EGR) to meet the levels, Caterpillar chose to use its own technology. Instead of not adding exhaust gasses to the combustion process, ACERT relies on aftertreatment to lower emissions. Cat received conditional certification from EPA to sell on-highway truck engines after October 1, 2002. However, those "bridge" engines fell short of the new federal emissions standards and were subject to fines for each one sold.