From the design angle, the new D12A engine was one of the largest engine projects from Volvo Trucks since the 1950s at the time. The basic design was still based on direct injection in-line six diesel engines around 12 litres displacement but with entirely different fuel and valve systems when compared with previous Volvo engines. Built at the purpose-built facility at Skövde on a fully automated line where the bulk of the engine assembly is done by robots and the final engine dressing is carried out manually. The D12A was designed as a "world engine" to be able to meet the latest demands in high power output, low fuel consumption and lower emissions with its single OHC (overhead camshaft) design, four valves per cylinder, and one centrally located electronic unit injector, integrated engine compression brake and two-piece, steel and aluminium pistons. The engine design left the door open for future upgrades in both power output and emission technologies.