In 1972, This Gas Turbine-Powered Volkswagen Bus Was the Future

Volkswagen made the first major mechanical update to the Bus when it rolled out the Type 4 flat-four, which is also known as the “pancake engine,” for the 1972 model year. The company simultaneously experimented with another, more innovative alternative to its original flat-four engine that never made it to production. In the early 1970s, engineers built and tested a gas turbine-powered Volkswagen Bus.

The idea of stuffing a turbine in a car wasn’t new. Chrysler began toying around with the technology in 1953 and famously released the aptly-named, Ghia-designed Turbine coupe a decade later. Across the pond, Rover put a turbine in several prototypes, including a race car designed jointly with British Racing Motors (BRM) that was entered in the 24 Hours of Le Mans several times starting in 1963. While neither company managed to push the turbine toward the automotive mainstream, Volkswagen was intrigued enough by the idea of making a car that sounded a little bit like an airplane to give the project a shot.

Williams Research Corporation, a Michigan-based company that specialized in making turbines for Navy target drones and other relatively small applications, helped Volkswagen develop a 374-pound, twin-shaft turbine with an integrated reduction gear that fit in the bay designed for the flat-four. In an odd twist of fate, Sam Williams founded the firm that bears his name in 1955 after leaving Chrysler’s turbine program.

Volkswagen linked the turbine to an automatic transmission sourced from the 1600. This wasn’t a pie-in-the-sky concept built to turn heads on the auto show circuit. Called Kombi GT 70, the prototype put 75 horsepower under the driver’s right foot and could reach a top speed of 75 mph. Both figures were a little higher than the ones posted by a standard Bus. Beyond the extra power, engineers noted that they liked the turbine because it was compact enough to stuff in a tight space, and it could run on diesel or gasoline.

With the exception of a vented engine cover, the turbine-powered Bus looked pretty much like a regular bay-window. It’s the same story inside, where one of the bigger changes was powertrain-specific gauges.

Details about Volkswagen’s short-lived turbine program are few and far between, but poor fuel economy likely contributed to the drivetrain’s demise, especially in the wake of the 1973 oil crisis. Like many of its peers and rivals, the brand instead invested in diesel engines as a more efficient alternative to gasoline. Its first diesel was a 1.5-liter naturally-aspirated four-cylinder rated at 50 horsepower and made available on the original Golf in 1976. Diesel power later spread across the range. The second-generation Bus was never made available with a diesel engine but its successor, the Vanagon, gained a diesel option for 1982.

Volkswagen used the bay-window Bus to test numerous other technologies. Gustav Mayer, who was the head of Transporter development in the 1970s, built a four-wheel-drive Bus to explore the Sahara. Five additional prototypes were built and tested; Some were even given to police forces. The project didn’t receive the green light for production, but it paved the way for the Vanagon Syncro launched in 1985.