VW GTICall it a double-whammy, but VW calls it a SuperTurbo. Actually it is 'SuperTurbo Compounding' by Eaton, the likely supplier of the system. Essentially, you have a turbocharged engine that is also fitted with a supercharger. The complexities of handling this type of forced induction have limited its automotive application. The supercharger provides instantaneous power. Once the turbo is providing boost, the supercharger's clutch is disengaged and it is closed off from the induction system, allowing the turbo to take over completely. The result is a power plant that has none of the usual performance compromises found in typical forced-induction scenarios. The numbers are quite impressive. VW will initially offer the system in its European line up. The first engine will be a 1.4-liter four cylinder that will produce 140 hp and 184 lb-ft of torque, with a performance version producing 170 hp and 199 lb-ft. That is crazy power out of such a small displacement engine. Fuel economy is another benefit to this approach. VW plans to offer this power plant up against turbodiesel engines, which could also benefit from this system. VW is also working on 1.6 and 2.0-liter versions of the SuperTurbo, which would produce 195 hp and 240 hp respectively. While all this power sounds great, we wonder how reliable the entire system will be. VW four-cylinders are normally very robust. We worry about the electro-mechanical reliability of the system. What happens when the supercharger's clutch fails to disengage or engage? Obviously there are a lot of interdependencies involved. We're hoping that Eaton and VW have developed enough 'interlocks' to prevent one failure from jeopardizing the entire system.