A Volkswagen Passat than can run on natural gas or petrol has had its world debut at the Geneva Show. And although the Passat Estate TSI EcoFuel is a concept, Volkswagen says that the vehicle will be introduced in mainland Europe (ie. in markets in which the fuel is supported) in both saloon and estate body styles before the end of the year. However sales of the vehicle in the UK are yet to be confirmed.
The Passat Estate TSI EcoFuel is powered by a 1.4-litre TSI 150 PS engine running on either natural gas or petrol. The car produces fewer emissions when compared to a conventionally-fuelled Passat Estate TSI. The engine features both a supercharger and a turbocharger operating sequentially to provide relatively high power outputs from a small capacity engine.
In order to allow the engine to cope with the additional loading encountered through the burning of natural gas rather than petrol, significant changes have been made. The valves, piston rings and the pistons themselves are all uprated to cope, while the turbocharger has also been replaced with a smaller unit. A new engine management computer controls the switch between conventional fuel and natural gas.
The natural gas is stored in a trio of tanks with a combined capacity of 22 kg mounted beneath the boot floor. This is supplemented by a 31 litre tank for conventional petrol. Between the two tanks the Passat Estate TSI EcoFuel has a theoretical range of over 490 miles.
The result is a non-diesel vehicle that meets the Euro 5 standards, greater economy and lower emissions. It has a top speed of 130mph, the capability to accelerate from 0 to 62 mph in 9.7 seconds, and in normal conditions the vehicle consumes 5.2 kg of natural gas every 100km.