The steepest challenge faced by every pioneering auto builder was finding a suitable source of power. Petroleum-fueled internal combustion (IC) powerplants, steam engines, and electric motors all energized the drive to replace horses with horsepower. When one contraption lacked the gumption to climb hills, resourceful horseless-carriage constructors simply added a second powerplant as if they were harnessing another mare to the team. Later, we dubbed these concoctions hybrids.
1894: Italian textile manufacturer Count Felix Carli added a box of tensioned rubber bands to double the power available in his electric tricycle.
1897: Justus Entz, chief engineer at a Philadelphia battery company, built the first carriage powered by an IC engine assisted by an electric motor. Sluggish performance was reported. Worse, the experiment was destroyed when a rogue electrical spark ignited the fuel tank.
1899: Two hybrids appeared at the Paris Salon. One from a Belgian firm featured parallel IC and electric propulsion using a system similar to Honda's Integrated Motor Assist. A French design employed a series configuration; here, an IC engine powered a generator which supplied current to two electric motors driving the wheels. In the decade that followed, several other makers touted series hybrids at the Paris Salon.
1900: Like Henry Ford, Ferdinand Porsche's first career stop was in the electrical field. He earned two related patents in 1897: one for a motorized wheel hub, the second for a series-hybrid propulsion system. While employed by Jacob Lohner, Austria's leading vehicle manufacturer, Porsche brought these concepts to fruition. After a front-drive Lohner-Porsche carriage sparked interest at the 1900 Paris Salon, a four-wheel-drive version was built. The latter model's storage battery weighed nearly two tons so Porsche added a pair of generators driven by 2.5-hp Daimler IC engines to extend operating range. What Porsche called "mixte" (mixed) propulsion successfully powered military vehicles, fire-fighting equipment, and Mercedes automobiles.
1902: A series-hybrid runabout constructed by Knight Neftel competed successfully against steam and gas-powered buggies in the New York to Boston Reliability Test.
1915: The Owen Magnetic used a conventional IC engine powering a generator supplying electricity to a drive motor, thereby eliminating gear changes.
1916: Two prominent electric-vehicle makers - Baker of Cleveland, Woods of Chicago - both offered hybrid propulsion. The latter could be driven using gasoline, electric, or both motors. Performance claims for the Woods Dual Power were a top speed of 35 mph and 48 mpg fuel efficiency. Since it cost as much as a Cadillac V-8 with electric starting and twice as much power, few were sold.
1938: GM's Electro-motive Corporation began supplanting steam locomotives with diesel-electric hybrids. A large IC engine driving a generator supplies power to electric motors which drive the engine's wheels. No electrical energy is stored on-board.
1939: Electrogear buses manufactured and operated in Philadelphia used a differential transmission capable of blending IC and electric power for heightened efficiency.
1944: P.M. Heldt's Torque Converters or Transmissions for Use with Combustion Engines in Road and Rail Vehicles, Tractors and Locomotives was published. This handy reference soon became the preferred source of inspiration for hybrid engineers the world over.
1969: GM engineers in England constructed a two-seat minicar with a parallel-hybrid drive, a 35 mph top speed, and a 150-mile range.
1970: The Clean Air Act renewed interest in hybrid propulsion. Four TRW engineers working under Department of Health, Education, and Welfare (EPA precursor) auspices invented a clever electromechanical transmission for hybrid vehicles.
1973: The first energy crisis intensified the search for more fuel efficient transportation.
1974: Dr. Victor Wouk and Dr. Charles Rosen installed what they termed a compound parallel hybrid propulsion system in a Buick Skylark. The five-passenger, 4100-pound sedan demonstrated a 200-mile range, 80-mph top speed, and reductions in fuel consumption and emissions.
1976: After Congress passed the Electric and Hybrid Vehicle Research, Development, and Demonstration Act, General Electric was tapped to construct a parallel-hybrid sedan capable of doubling fuel efficiency.
Toyota built its first hybrid, a small sports car with a gas-turbine generator supplying current to an electric motor.
1980: Briggs & Stratton sponsored the construction of a six-wheel compact with parallel-hybrid propulsion. The 26-hp (combined), 3200-lb multi-mode vehicle had a 75-mph top speed.
1989: Audi presented the Duo experimental vehicle with an IC engine powering the front wheels and electric rear drive.
1993: The Clinton-Gore administration created a Partnership for a New Generation of Vehicles (PNGV) between the United States Council for Automotive Research (formed in 1992), and a network of universities, national labs, federal agencies, and suppliers. The goals were 80-mpg concept vehicles by 1999 followed by production-feasible prototypes by 2004. No prototypes emerged, though GM's Precept did achieve 90 mpg on diesel fuel.
Toyota's exclusion from PNGV moved chairman Eiji Toyoda to ponder more efficient automobiles. Takeshi Uchiyamada was assigned the chief engineer's job for a project called G21 (global car for the 21st century).
1994: The original goal of a 50-percent efficiency gain was doubled by Toyota's new engineering executive vice president Akihiro Wada who targeted the following year's Tokyo Motor Show as the ideal opportunity for displaying a hybrid concept.
1995: While the Toyota Prius concept was under construction, eighty research engineers brainstormed on a practical hybrid powertrain. The final Toyota Hybrid System (THS) selected in June combined one IC engine, two electric motor-generators, and a planetary gear set in a configuration identical to TRW's 1970 electromechanical transmission. The first THS prototype ran in December.
1996: The Prius's market introduction was accelerated two years so Japanese customers would be on the road before the Kyoto Conference on Global Warming held in December 1997.
1997: Two hybrid vehicles were introduced for sale. In Europe, Audi's A4 Avant Duo used a 90-hp turbo diesel and a 29-hp electric motor to drive the front wheels. In Japan, the Toyota Prius teamed a 57-hp gasoline engine with a 40-hp electric motor.
1999: At the North American International Auto Show, Honda presented a two-seat concept called VV with a three-cylinder gasoline engine and Integrated (electric) Motor Assist powering the front wheels. It went on sale later in the year as the Honda Insight with EPA ratings of 61 mpg in city driving and 70 mpg on the highway.
During a five-year GM-Toyota technical liaison, the hybrid portion of their cooperative effort was called Synergy.
2000: A second generation Toyota Prius arrived for sale in the US with more power, better acceleration, and lower emissions. than the previous Japanese model. For marketing purposes, the name Toyota Hybrid Drive evolved to Toyota's Hybrid Synergy Drive.
2003: After the new third-generation Prius earned several "Of the Year" awards, Toyota Motor Sales president Jim Press called it, "The hottest car we've ever had." GM began manufacturing its Two-Mode diesel-electric propulsion system for global transit bus use. There were few takers for the simple electric-assist hybrid system GM offered in Chevrolet Silverado and GMC Sierra pickup trucks.
2005: BMW, DaimlerChrysler, and GM form a Global Hybrid Cooperation to develop Two-Mode for various car and light-truck applications.
2006: Chevrolet, Ford, GMC, Honda, Lexus, Mercury, and Toyota currently offer a dozen hybrid car and truck models. Industry forecasters predict that annual global hybrid sales will exceed one-million units by 2010.
2007: At the North American International Auto Show, Chevrolet's Volt series-hybrid sedan forecast the introduction of lithium-ion batteries capable of providing 40 miles of electric-driving range. GM began manufacturing Two-Mode transmissions at a Baltimore facility and announced future applications ranging from front-drive Saturn sedans to Cadillac Escalade SUVs.
2008: Deliveries of the 2008 Chevrolet Tahoe and GMC Yukon Two-Mode hybrids will be followed by Dodge Durango and Chrysler Aspen models by the end of the year.