Briggs and Stratton that was green, even off the grass

Built by a company best known for its lawnmower engines, the Briggs & Stratton Gasoline/Electric Hybrid aimed for one thing and one thing only in the gasoline-crisis-plagued 1970s: efficiency.

Category: Concept car

Introduction: 1979 San Francisco Import Car Show

Inspiration: Montreal-based Marathon Electric Vehicles contributed the platform, complete with a unique solution to the challenge of lugging 1,000lbs of lead-acid batteries: a second rear axle. The resulting six-wheel layout offered an improved ride, with reduced rolling resistance compared to four heavily loaded tires.

Whereas many innovative concepts treated styling as an afterthought, Briggs & Stratton commissioned industrial designer Brooks Stevens – he of Willys Jeepster, Oscar Mayer Wienermobile and Evinrude outboard-motor fame, as well as the coiner of the controversial phrase “planned obsolescence” – to produce this design. For expediency, the Hybrid used the doors and windshield from the first-generation Volkswagen Scirocco sports hatchback, but everything else was purpose-built.

Particulars: The Briggs & Stratton Hybrid employed one of the company’s ubiquitous air-cooled industrial engines, familiar to generations of lawn-mowing teenagers and homeowners. Matched to an off-the-shelf, 18-horsepower, 700cc twin-cylinder gas engine was an 8hp electric motor. The parallel-hybrid configuration meant the car could run solely on gas or electric power, or a combination of the two.

In its March 1980 issue, Motor Trend found the car’s top speed to be 55mph, negating the possibility of 0-60 acceleration testing. But the editors did manage to document the 34.35 seconds needed to reach 50mph. The car could drive between 30 and 60 miles on electric power alone, but observed acceleration to 50mph without gas-engine assistance was an abysmal 45 seconds.

Time, however, has proved the saliency of Briggs & Stratton’s thinking, particularly around the notion that plug-in hybrid technology could find ready application in efficiency-oriented family cars. If nothing else, the Hybrid’s less than blistering performance serves to illustrate why a quarter-century would pass before plug-in hybrids would catch on.

Innovations: The Hybrid’s huge battery pack was carried on a virtual trailer contained within the car’s body. It was an impressive, unorthodox solution for the age, long before lighter, more energy-efficient nickel-metal hydride and lithium-ion cells would find their way into automotive applications.

Initially, the Hybrid lacked regenerative braking – a hallmark of modern hybrids. Briggs & Stratton’s engineers upgraded the vehicle with an information-age silicon speed controller, replacing clunky, noisy steampunk relay switches. The change made the car more refined to drive and added regenerative braking for improved driving range, further setting the table for today’s plug-in hybrids.

Influence: The Briggs & Stratton team clearly understood the technical challenges faced by plug-in parallel hybrids, if not necessarily the costs of scaling production of the various components to make them feasible. In mass production, Briggs estimated that such a system would cost $1,500 in 1980 dollars – the equivalent of roughly $4,300 today, or about half of the premium commanded by the Ford Fusion Energi plug-in hybrid over its conventional hybrid counterpart.

Whereabouts: The Hybrid is housed inside the Briggs & Stratton Powerhouse Museum at the company’s headquarters in Milwaukee, Wisconsin.

Hindsight: The engineers at B & S truly were on to something, even if the technology was not ready for market. “We feel that a properly designed parallel hybrid can virtually eliminate all the performance-based barriers to customer acceptance of an electric car as a primary personal car,” the company stated at the time.

Today’s Ford Fusion Energi, as well as the Toyota Prius PHV, Chevrolet Volt and many others, owe a bit of their drivability to the fundamental soundness of the plug-in parallel hybrid concept pioneered by Briggs & Stratton in 1979.