The Cat® C6.6 is a 6.6 liter (403 in3) displacement, six-cylinder, in-line configured engine that utilizes the Caterpillar Common Rail fuel system for fuel delivery. It uses ACERT™ Technology, a series of Caterpillar engineered innovations that provide advanced electronic control, precision fuel delivery and refined air management, resulting in outstanding performance and lower emissions. The C6.6 with ACERT Technology offers a compact design with big, heavy-duty engine features for outstanding durability, reliability and performance. The C6.6 incorporates a new cross flow cylinder head design, 4 valve head and an ADEM™ A4 electronic controller. The C6.6 also features proven cylinder block, pistons and crankshaft and incorporates the common rail fuel system. ACERT™ technology enables the C6.6 engine to meet the U.S. EPA Tier 3, European Union Stage IIIA and Japan Ministry of Land, Infrastructure & Transport Step 3 emissions standards, which dramatically reduce nitrogen oxide (NOx) and other emissions. ACERT™ technology used on the C6.6 consists of three basic building block systems: electronic control, fuel delivery, and air management. These have been refined to control the combustion process to a higher degree than ever before possible.