Decade of the Toyota Prius Hybrid

Ten years after the introduction of the first mass produced gas-electric hybrid, the Toyota Prius is now the icon of the green vehicle movement. In late 1997, the Prius went on sale in Japan after overcoming considerable technological, engineering, and developmental challenges. It hasn't stopped to catch its breath since.

This first generation production Prius was launched exclusively in the automaker's home market before going international. Clearly, so much was on the line. The gasoline-electric hybrid was a new concept to consumers. Getting it right the first time was essential. Toyota didn't want the hybrid experience to parallel that of quick-to-market passenger car diesels in America that occurred decades ago. As we know, diesel is still working to overcome that negative reputation in the States.

This groundbreaking car's name was carefully considered, as is always the case with new car models. "Prius," which in Latin means "to go before" or "proceed," seems especially appropriate for Toyota's pioneering hybrid effort. In 1994, Takeshi Uchiyamada was assigned to lead a team to design an eco-friendly car of the 21st century. Toyota had been working various forms of hybrid technology on and off for some time. The company's G21 (Global 21st century) project led to the Prius concept car that debuted at the Tokyo Motor Show in 1995. Despite ongoing technical challenges, the program was not only pushed forward, but accelerated toward production.

The Generation I Prius was introduced to the Japanese market in December of 1997 with a powertrain known as the Toyota Hybrid System, or simply THS. It featured a 58 hp gasoline engine and 40 hp electric motor. The D cell-size battery pack in the Gen I Prius offered 288 volts. Toyota had problems with a small number of the battery packs, which the company replaced for free.

Improvements to the original design encouraged Toyota to go global with the Generation II Prius in 2000. While this was being implemented, Honda brought the slippery two-seater Insight hybrid to America in 1999, beating Toyota to the gasoline-electric hybrid punch and claiming the title of being the first hybrid in the American market. It was a coup ... but it didn't overcome the unstoppable force that was destined to become the most popular hybrid on the road.

The 2001 model year Generation II Prius, introduced in America in August of 2000, was a major evolution technically and better suited for the U.S. market. Toyota described the 2001 Prius as a stylish, roomy, five-passenger sedan with a base price of $19,995. What really got consumer's attention, however, was the preliminary EPA fuel economy rating of 52 mpg in the city and 45 mpg on the highway. While this fell short of the Honda Insight's even more amazing EPA estimated 61 city and 70 highway mpg, it was eye-opening for a four-door sedan and also clean enough to be certified as a SULEV (Super Ultra Low Emissions Vehicle), making it one of the cleanest on the road.

The new Prius, built at the Motomachi Plant in Toyota City, Japan, offered more power for better acceleration and a new modular battery-pack design. The new battery design was both smaller and more powerful, with typical Toyota reliability. Unlike the Gen I Prius, the smaller battery pack allowed the rear seats in the Generation II car to fold forward for more flexible cargo handling. The United States, which is Toyota's largest market, would have demanded more performance than the original car offered. The Generation II Prius delivered the needed baseline performance with gasoline engine output increased from 58 hp to 70 hp. The electric motor yield also increased slightly to 44 hp with 258 lbs-ft of torque.

The current Prius, known as the Generation III car, was introduced in 2003 as a 2004 model. For the American market, Toyota calls this car the Generation II Prius, somewhat clouding the chronology. The new Prius was the first with Toyota's all-new Hybrid Synergy Drive technology. Power from both the gasoline engine and electric motor increased sufficiently to cut 0-60 mph acceleration times by nearly 2.5 seconds. The result was a super high mileage sedan with performance on par with a traditional four cylinder mid-size car.

The latest generation features a 1.5-liter DOHC four-cylinder gasoline engine with Variable Valve Timing with intelligence (VVT-i) that produces 76 hp and 82 lbs-ft of torque. The gasoline engine is joined by a 67 hp permanent magnet AC motor that delivers 295 lbs-ft of torque between 0-1200 rpm. A sealed 201 volt nickel-metal hydride battery provides the power. Estimated fuel economy with EPA's 2007 rating system was the best in the business, with 60 mpg in the city and 51 mpg on the highway. Those numbers readjusted to 48 mpg city and 45 mpg highway with the new 2008 EPA test procedures.

Prius owners make more of a statement with the latest generation cars, too. The newer design, a marked improvement over the original and somewhat quirky-looking Prius, remains distinctive even four years after its debut. Its Jetsons-like profile is futuristic and aerodynamic with a high-tech appeal. It's no secret that this distinctive profile prompts many buyers to choose the Prius, since others know they're piloting an environmentally positive car at a glance. The car's interior is roomy and comfortable, though a few of the unique design elements take some acclimation.

Success with Prius has driven Toyota to implement its Hybrid Synergy Drive in other popular platforms including the Highlander SUV, mainstream Camry sedan, and a variety of Lexus models including the LS, GS, and RX lines. As a result, Toyota delivered the 1 millionth hybrid in June of 2007, with over half (541,210) delivered in the United States. Toyota is on track to sell over a quarter million hybrids in 2007 alone.

A decade after its introduction, Prius is still leading the way in many respects. It has fielded a concept Prius GT and established a land speed record at Bonneville with a specially prepared Prius. What's next? Maybe a plug-in Prius that gets over a combined 100-plus mpg. Toyota has now embarked on a plug-in hybrid vehicle (PHEV) development program and is fielding test examples of Prius PHEVs on American highways. And, just maybe ... could there be a consolidation of Toyota's hybrids into an all-new Prius brand? There's no telling. Seemingly, there's just no stopping this groundbreaking vehicle.