, was introduced in 1979 as Briggs & Stratton's answer to high quality commercial-duty engines produced by competitors. These engines include heavy-duty features such as Stellite exhaust valves, upgraded bearings, cast iron sleeved cylinder bores and high-capacity air cleaners. The Briggs & Stratton Gasoline/Electric Hybrid Car – In 1980, at the tail end of the energy crisis, Briggs & Stratton developed the first gasoline-electric hybrid automobile concept car. "The Hybrid" was designed by Brooks Stevens, had six wheels and was powered by a twin-cylinder 16 hp (11.9 kW) Briggs & Stratton engine and a large bank of 6v lead-acid electric batteries. Only the second axle was driven, with an extra rear axle added to support the weight of the batteries. Magnetron Ignition – This solid-state ignition system introduced by Briggs & Stratton in 1982 eliminated the points-and-condenser system, the performance of which steadily degraded between required periodic maintenance service. Magnetron was made available for retrofitment to Briggs & Stratton engines made since 1963. Competitor Tecumseh had made a capacitor discharge ignition setup since 1968 for their cast iron engine models, expanding its availability and making it standard equipment on vertical shaft engines powering lawn mowers in late 1976, five years before the advent of the Briggs Magnetron. Defunct competitor Clinton Engines commercialized a piezo "Spark Pump" ignition without breaker points in the early 1960s. Logo history The Briggs & Stratton logo was always a masthead, but it has been changed several times over the course of the company's 80-plus years. Pre War logos (1931–1943) – This logo started off with a diamond shape and read Briggs & Stratton and its home city of MILWAUKEE, WIS., U.S.A. below it; in the middle, it had the words 4 CYCLE on the top mast and the words GASOLINE MOTOR and phrase MADE IN U.S.A. on the bottom mast. About 1934 Briggs & Stratton added the more familiar shape of a diamond split across the center with a banner. Gold Logo (1948–1963) – This logo had the name BRIGGS STRATTON and its home city of MILWAUKEE, WIS., U.S.A. below it; in the middle, it had the words 4 CYCLE on the top mast and the words GASOLINE ENGINE and phrase MADE IN U.S.A. on the bottom mast. Gold Logo (II) (1963–1976) – Although similar to the last logo, this had differently arranged wording: The name BRIGGS STRATTON was written in a new logotype, however,