August 26, 2005
VW to debut dual turbocharged/supercharged engine
Frankfurt, Germany – Volkswagen will introduce the first of a newly-developed gasoline engine family that combines downsizing with dual supercharging and turbocharging at the International Motor Show in Frankfurt in September, according to the Green Car Congress. The engine will provide high power output and maximized torque with low fuel consumption.
The first dual-charged engine will be a 1.4-litre in the new Golf GT 1.4 TSI. The engine is rated at 168 hp but with a fuel consumption of 7.2L/100km (39 mpg Imperial). By contrast, the current 2.0-litre GT produces 148 hp while using 7.8L/100km (36 mpg Imperial). VW will also preview a new Touran with the TSI engine, which is due to launch in Germany in the first quarter of 2006.
The dual system overcomes the disadvantages of both types of chargers: the supercharger’s parasitic engine load, and the turbocharger’s lag time. In the new combined system, the mechanical compressor operates at low speeds to increase low-end power. At middle revs, the turbocharger engages. Once it reaches sufficient speed to provide boost, a clutch will disengage the supercharger and it will be bypassed. While neither increases fuel economy by itself, they enable the use of a smaller, more fuel-efficient engine.