W8 engine

A W8 engine is an eight cylinder piston engine in a W configuration, or two juxtaposed 15 degree V4 engine blocks, mounted at 72 degrees to one another and coupled to one crankshaft.

The W8 can be imagined as flat plane crank V8 made with VR4s instead of inline 4s. Nearly-square dimensions mean the large engine will fit in the space typically alloted for a V6.

The W8 was used in the Volkswagen Passat from 2001 to 2005, but sales were minimal at only 10,000 units worldwide per year. The 4.0 litre engine produced 270 hp @ 6000 rpm and convert|273|ft.lbf|N.m|abbr=on of torque at 2750 rpm, yet was considered a fuel-efficient 8 cylinder engine due to the design. It also had a two stage resonance induction system to boost cylinder filling across the engine speed range. It had dual overhead camshafts in each cylinder head and twin balance shafts to smooth out residual vibrations inherent in the layout. One additional advantage was that the W8 shared some components and machining with narrow-angle VR5 and VR6 engines, leading to cost reduction in one of the most expensive engines Volkswagen has ever produced.

The 2006 redesign of the Passat, with its engine re-orientation, was no longer equipped with the W8, and the 'large' 3.6 liter VR6 has replaced its position.