The TDI (turbo direct injection) turbodiesel V-10 for Volkswagen AG’s all-new Touareg SUV and Phaeton sedan – both VW flagships in their class – comes to market claiming the title of the world’s most powerful passenger-car diesel.

Volkswagen’s all-new V-10 turbodiesel displaces 5L and produces 313 hp and 553 lb.-ft. of torque.

Displacing 5L, the SOHC V-10 turbodiesel develops 313 hp at 3,750 rpm and a thunderous 553 lb.-ft. (750 Nm) of torque at 2,000 rpm.

Aside from its estimable power figures, the V-10 embodies unique design features that break new ground in engine architecture. It essentially consists of two 5-cyl. engines –joined at a 90-deg. angle – that are completely separate, though mechanically and electronically coupled.

For weight reduction, the cylinder block and crankcase are aluminum castings. To handle the combustion forces, the main bearings are located in an innovative cast-iron tunnel that is clamped by lengthy studs to the cylinder heads. Alloy cylinder bores are plasma-coated by a VW process used for the first time on a production diesel. This treats the cylinders with a few-microns of surface layer said to provide permanent resistance to deformation and wear.

Cross-flow, 2-valve cylinder heads with direct injection use VW’s established unit injectors running at up to 30,000 psi (2,050 bar). Compression ratio is 18:1. Individual intake manifolds for the two cylinder banks are independent systems, each with its own air cleaner, hot-film airflow meter, exhaust gas recirculation circuit and throttle valve. The manifolds are fed with combustion air via matched intercoolers from twin turbochargers. The turbos have electrically variable turbine blades said to provide more accurate control than with typical pneumatic angling.

Touareg CUV V-10 is backed by 6-speed automatic transmission and AWD transfer case.

Camshafts and unit injectors are driven by a helical geartrain from the flywheel end of the engine. All main auxiliaries, including the alternator, water pump, power-steering pump and air-conditioning compressor, are located within the engine vee; All are driven by the timing gear – the engine uses no belts. To enhance refinement, these units are housed in a casing that is acoustically isolated from the cylinder block.

Vibration is smoothed by uniform 72-deg. ignition spacing between cylinders, achieved with 18-deg. crankpin spacing. With a balance shaft rotating at the same speed as the crankshaft but in the opposite direction, the V-10 is claimed to match any V-12 in noise, vibration and harshness.

For the V-10, new-generation computing power was developed by Robert Bosch GmbH. The engine-management computer handles precise synchronization and load distribution of the two individual-but-joined 5-cyl. banks. A 32-bit, dual-function microprocessor, described as a “master-slave system,” controls and coordinates the fuel-injector elements, throttle valves and turbocharger control for co-dependent functions of this exceptionally complex diesel.

In the Touareg SUV, the engine is backed by an Aisin AG 6-speed Tiptronic automatic transmission and 2-speed transfer case incorporating the center differential. This inter-axle unit has a continuously adjustable multi-disc clutch serving as a differential lock that varies the front/rear power split according to traction requirements, controlling engine torque and wheel slippage.