Think turbocharger and you may think high performance, but the latest generation of cars are using turbochargers in order to maintain performance whilst engine capacity decreases in the push for improved fuel economy.
Volkswagen is no stranger to forced induction, having used turbochargers on diesel vehicles for many years and on gasoline vehicles more recently in the last few generations of Golf and Passat. Those cars have mostly used 2.0 liter engines though - a capacity that dwarfs engineering firm Bosch's latest 1.2 liter, 3-cylinder Passat.
Along with partner Mahle, the Bosche Mahle Turbo Systems Passat is an example of "extreme downsizing" and an exercise in showing that you need not sacrifice performance in the pursuit of high economy.
Mahle Powertrain has designed the car's 1.2 liter, 3-cylinder engine and equipped it with a turbocharger. The end result is 161 horsepower at 5,000rpm - significantly more than the smallest engine currently available overseas, a 1.4 liter, TSI direct-injection gasoline 4-cylinder that produces 121 horsepower. Torque from the 3-cylinder is an impressive 210 lb-ft from 1,600 to 3,500rpm.
On the European combined driving cycle (essentially a mixture of city and highway driving), Bosch rates fuel consumption at 40 miles per gallon. The 1.4 liter achieves slightly less, at 39mpg.
Bosche Mahle Turbo Systems has already signed a contract with a German automaker but insists the use of a Volkswagen for the 3-cyl demonstrator is no guarantee that Volkswagen is the customer. BMW is already rumored to be researching 3-cylinder engines for the next generation 3-Series.
Downsized turbocharged gasoline engines are becoming more popular worldwide as smaller capacity diesel engines are both expensive to produce and unpopular in some markets, notably the U.S. They're also unfavorable in terms of emissions - despite the advances in recent years - compared to modern ultra-clean gasoline engines.