1980’s Briggs & Stratton Hybrid is your 30 mpg six-wheeler

Briggs & Stratton makes mostly carburetor-equipped, air-cooled engines that may not produce more than 40 horsepower but, in exchange, are likely to run tirelessly on the most basic of fuels, powering everything from generators to your cherished lawn mower.

Back in 1978, just before the start of the second oil crisis, the company also wanted to demonstrate that cruising at the national speed limit of 55 mph could be done in a much more efficient manner, using no more powerful unit than an 18-horsepower flat-two engine. Air-cooled and carbureted, displacing 694 cc—almost the same as what you find in Fiats of the ’50s.

Using Ford Pinto and Volkswagen Scirocco parts, along with custom panels created by Brooks Stevens and his son, Briggs & Stratton built a six-wheeler concept, giving the 12 Globe Union 6-volt batteries their own driven axle (and the press something to talk about). With this additional 72-volt system at the rear, the Milwaukee company’s parallel hybrid was capable of 68 mph on its combined power, as evidenced by a closed circuit driven by none other than Richard Petty. Those trusty 6-volt lead-acid batteries would also grant Briggs & Stratton’s 3200-pound hybrid a pure electric range of at least 45 miles, which came handy on the way up towards that 55 mph cruise, since this machine was built to return a combined mileage of around 30 mpg.

Disc brakes at the front to handle the mass, a Recaro interior, and the unmistakable sound of an air-cooled industrial flat-two. An American hybrid finished in 1980, a year after Fiat sent its 131 Ibrido to Detroit. Powered by a combination of a 903-cc Fiat 127 engine and a 26-horsepower electric motor, the Ibrido has proved another parallel hybrid that arrived too early for human consumption.

1988 was the last time this six-wheeler was running, but when Jay Leno called, Briggs & Stratton engineering technician Craig Claerbout and his team were more than happy to get it back on the road: