We’ve come a very long way since 1980 and this gas-electric hybrid cobbled up by venerable lawn mower maker Briggs & Stratton. In comparison to Toyota’s Prius, first shown in 1995, it’s crude and primitive, really not significantly different than the system used in the Belgian 1899 Pieper, which went on to be used by another Belgian firm, Auto-Mixte (Ferdinand Porsche’s 1900 Mixte was a serial hybrid).
In 1980, everyone was working on ways to reduce fuel consumption, and presumably B&S figured that a hybrid was a way to utilize a much lower output gas engine, as in one of their 18hp air cooled twins, as also used in garden tractors and industrial applications.
Why the third axle? To help support the weight of the bank of lead acid batteries at the rear.
Here’s how it worked: the 694 cc gas engine was mounted ahead of the electric motor, with a one-way clutch between them. The 8 hp (contiguous) DC electric “coffee can” motor then fed into a Ford Pinto four speed transmission, drive shaft and rear axle.
The idea was that EV-only mode would be used for lower speed in-town driving (up to 40 mph), with the gas engine cut in to augment acceleration and cruising at higher speeds (55 maximum). And when the batteries’ limited range (not stated) ran out, the gas engine could be used to keep the party going, although undoubtedly none to briskly with 18 hp.
The body was styled by Brooks Stevens Associates. The doors (and dash) are from a VW Scirocco, and the rest are mostly custom built panels.
Not surprisingly, only this one prototype was built, but it’s still in excellent condition, and Jay Leno did a video on it. I had to hit Pause after 10 minutes, as I find him rather unwatchable, but that’s just me. It’s a slow as the B&S is.