One can view the W8 motor from two different perspectives - it can be seen as a W12 with one cylinder from each bank of cylinders lopped off, or as half a W16. Either way, the smallest W-layout motor would be the only 8-cylinder capable of fitting into the engine bay of a Passat, whose Torsen-based all-wheel drive system ate up the remaining space. Besides, fitting a conventional V8 wouldn't have had the technical prestige that the brand's new premium image required.
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| Due to its design, the W8 engine took up nearly the same space as the conventional 2.8-liter V6 in the Passat's engine bay. (Photo: Volkswagen Canada) |
Like the VR6 before it, the W8 was truly an engineering marvel. It crammed eight cylinders in an area displacing four liters while being only 42 cm in length, a space in which the Audi-derived conventional 2.8-liter V6 struggled to fit. In order to keep within the size constraints of the Passat's tight dimensions, a highly complex design was needed requiring the best components that the automotive industry had to offer. Such advanced components included a flat-plane crankshaft, complex valve gears and the requisite twin balancer shafts.
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| Complex designs that work well in theory don't always result highly when it comes to dependability, and therefore the W8 had, and still has its fair share of problems. (Photo: Rob Rothwell, Canadian Auto Press) |
Of course, the most technically complex designs that work well in theory don't always result highly when it comes to dependability, and therefore the W8 had, and still has its fair share of problems. First and foremost, it was an expensive motor to produce. The intricacy and sophistication of the design meant that casting and building the W8 was downright expensive. Also, because of the size restrictions imposed on the motor the W8 required narrower tolerances, including thinner castings which are more difficult to execute. The space constraints also limited airflow, therefore restricting optimal breathing. The end result proved to be less than ideal output figures, despite the engine's large bore and stroke, variable valve timing and two-stage variable exhaust. In the end the W8 managed to make only 275 horsepower and 273 lb-ft of torque, hardly enough to compete in a market where smaller displacement, less sophisticated, cheaper V6 engines are making more.