The Cat C15 ACERT engine provides unequalled lugging force while digging, tramming and traversing steep grades. Torque rise effectively matches transmission shift points for maximum efficiency and fast cycle times. Mechanically Actuated, Electronic Unit Injection (MEUI™) high-pressure, direct injection fuel system electronically monitors operator demands and sensor inputs to optimize engine performance. Air-to-air aftercooling provides improved fuel economy by packing cooler, denser air into cylinders for more complete combustion of fuel and lower emissions. Oil coiled pistons increase heat dissipation and promote longer piston life. The crankshaft is forged and induction hardened for long-term durability. The Cat C15 engine features the optional Ventilation Reduction Package. The VR Package incorporates selective engine hardware and software to minimize diesel particulate matter in the engine exhaust. Engines equipped with the VR Package feature a significant ventilation rate reduction, a decrease in fuel consumption, and maintained or improved product performance. VR Package availability is subject to regional regulatory compliance. Optional U.S. EPA Tier 3 and EU Stage III compliant engine is also available. A Cat Diesel Particulate Filter can be used with the VR engine package. The filter compliments the VR engine by further reductions in particulate matter. Requires the use of 15 PPM ultra low sulfur diesel and CJ-4 low ash engine oil.