The 1980 Briggs & Stratton Hybrid concept car development costs were relatively low. The $250,000 cost was similar to what it cost other manufacturers to create hybrid concept cars. But the 1980 Briggs & Stratton Hybrid concept car incorporated some novel twists. Its gas engine, for instance, was a small 18-horsepower air-cooled twin that B&S had just introduced and wanted to showcase.
Then there was the chassis. Project engineer Bob Harkness, who was also vice-president of B&S research and development, saved time and money with the prototype by starting with a six-wheel platform from a small delivery van made by Marathon Electric Vehicles of Quebec, Canada.
Only the forward pair of rear wheels was driven; the ones behind were a "trailer" for almost 1,000 pounds of batteries, located just below a shallow luggage hold. These 12 batteries powered a small eight-horsepower Baldor electric motor that was coupled to the up-front gas engine via a Borg-Warner "Duo-Cam" automatic clutch. This arrangement allowed the powerplants to be used alone or in tandem (as selected by a simple dash-board knob), but there was no provision for "on-the-fly" charging.
Power was taken rearward via a conventional four-speed manual transmission from a Ford Pinto, which also donated drive axle, rack-and-pinion steering gear, and steering column.
Harkness liked the six-wheeler concept because it allowed a hindmost-wheel design whereby a depleted battery pack could be rolled right out and a freshly charged one rolled in. But besides resolving this and other practical engineering issues, Briggs & Stratton wanted its hybrid to deliver maximum mileage in any power mode without looking like an economy car.
Styling for the 1980 Briggs & Stratton Hybrid was entrusted to Kip Stevens, son of famous Milwaukee-based designer Brooks Stevens of Excalibur fame. The result was indeed stylish despite the inherent awkwardness of the six-wheel chassis.
Taking the windshield and dashboard of an early Volkswagen Scirocco, Kip crafted a sporty hatchback coupe in the contemporary vein with a jazzy interior featuring four-spoke steering wheel, trip computer, and genuine Recaro buckets.
There was also a rear seat, upholstered to match the fronts, but the slim hard bench afforded scant room because of the bulky battery pack behind and a tidy wheelbase of only 86 inches to the drive axle (a more generous 112 to the third).
To help compensate for battery mass, Stevens rendered the body in fire-retardant fiberglass. For the same reason, interior panels were made of light but strong Alucobond laminate, and all "glass" save the windshield was actually DuPont SAR (super-abrasion-resistant) Lucite.
Curb weight thus ended up at a reasonable 3,200 pounds, and Stevens minimized any visual heaviness by finishing the lower third of the body in slimming black, the rest in bright yellow.
But could it move? And move fast? See the next section for details on Hybrid performance.