Making clever use of the available components and technology, way back in 1980 Briggs & Stratton created a gasoline/electric hybrid.

As the United States struggled through two gasoline shortages in the 1970s, there was renewed, if brief, interest in alternative engines and powertrains. One of many companies to jump into the potential field was Milwaukee-based Briggs & Stratton, the well-known manufacturer of lawn and garden engines.

With the Briggs & Stratton Gasoline/Electric Hybrid, as it was called, the company had no intention of entering volume production. Rather, the mission was to create a promotional tool and to demonstrate the potential of smaller engines to automakers and other possible customers.

The Briggs & Stratton was a parallel hybrid, with a gasoline engine and an electric motor coupled in tandem via a Borg-Warner Duo Cam industrial clutch so the vehicle could run on either power source separately or on both combined. An off-the-shelf B & S Model 42 twin-cylinder opposed engine (694cc, 18 hp) provided the fossil-fuel power, while the  Baldor 72-volt, series-wound DC motor (8 hp continuous, 20 hp peak) was fed by a bank of 12 six-volt batteries stowed in the rear. A Ford Pinto four-speed manual transmission and rear axle tied it all together.

Renowned industrial designer Brooks Stevens, also of Milwaukee, and his son Kip Stevens created the hatchback exterior design (an early rendering is shown above). Like many one-off prototypes, the Briggs & Stratton borrowed freely from existing production vehicles. The doors, cowl, windshield and dash are Volkswagen Scirocco components, while the front suspension, brakes, and steering are the aforementioned Pinto.

The basic chassis was reportedly sourced from the Canadian-built Marathon C-360 electric utility van, which featured the same three-axle layout. With no drive or brakes, the rear tag axle’s sole purpose was to support the weight of the 1,000 lb. lead-acid battery pack. Total weight was 3,200 lbs with an overall length of 174 inches and room for two adults and two children.

According to Briggs & Stratton, the hybrid could cruise at 55 mph on both motors (the national speed limit was 55 mph at the time) or do 40 mph on battery power alone with a range of 40 miles. These performance stats are hardly impressive today, but to give credit where it’s due, the project got the most from the existing components and technology. And the result certainly achieved its promotional objective, receiving favorable exposure in Car and Driver, AutoWeek, and elsewhere. Briggs & Stratton still has the prototype in fine condition, and in 2020 it was featured, running and driving,  in an episode of Jay Leno’s Garage, which you see on YouTube here.