In the early 1990s, Toyota saw that environmental awareness and stricter emissions regulations would shape the future of the automotive industry. The company aimed to create environmentally friendly and efficient vehicles that meet future standards.
In 1997, Toyota launched the Prius in the Japanese market. It was the world’s first mass-produced hybrid car that combined gasoline and electric power to reduce fuel consumption and emissions. It made its worldwide debut in 2000.
The development of the Prius presented significant technological and market challenges, including designing an efficient hybrid powertrain, managing battery technology, and overcoming consumer skepticism about combining electric drivetrain systems with standard gasoline-fueled powertrains. But Toyota persevered, and its instincts proved prescient and transformative.
“Not only is the Prius the world’s first mass-produced hybrid car, but its technical and commercial success has prompted other car manufacturers to accelerate the development of hybrid cars,” said Nobuo Kawaguchi, professor in the Department of Computational Science and Engineering at Nagoya University and member of the IEEE. (Nobuo Kawaguchi) says: Japan Graduate School of Engineering. He is also the secretary of the IEEE Nagoya Section. “The Prius helped shape the role of hybrid vehicles in today’s automotive market.”
The Prius received the IEEE Milestone Award at a ceremony held on October 30 at Toyota City headquarters in Japan.
G21 Project
Development of the Prius began in 1993 with the G21 project, which focused on fuel efficiency, low emissions, and economics. According to a Toyota article detailing the history of the project, by 1997 Toyota engineers, including Takeshi Uchiyamada, who would become known as the “father of the Prius,” were satisfied that they had achieved all three goals.
The first generation Prius featured a compact design with aerodynamic efficiency. The groundbreaking hybrid system allows for a seamless transition between an electric motor powered by a nickel-metal hydride battery and an internal combustion engine powered by gasoline.
The vehicle design incorporates regenerative braking into the powertrain arrangement to increase the vehicle’s energy efficiency. Regenerative braking captures kinetic energy that would normally be lost as heat when conventional brake pads stop a wheel due to friction. Instead, the electric motor switches to generator mode, so instead of the motor driving the wheel, the wheel drives the motor in reverse. Using the motor as a generator slows the car down and converts its kinetic energy into an electric charge that is transferred to the battery to recharge.
“Not only is the Prius the world’s first mass-produced hybrid car, but its technical and commercial success has enabled other automakers to “We will accelerate the development of hybrid vehicles.” —IEEE Nagoya Branch Secretary, Nobuo Kawaguchi
According to the company’s “Leveraging Efficiency: A Deep Dive into Toyota’s Hybrid Technology” article, the breakthrough is Hybrid Synergy Drive, a system that allows the Prius to operate in multiple modes (electric-only, gasoline-only, or a combination). It was. Driving conditions.
A key component that Toyota engineers developed from scratch was the power splitter, a planetary gear system that allows for a seamless transition between electric and gasoline power, allowing the engine and motor to propel the vehicle in their respective optimal performance ranges. This arrangement helps optimize fuel economy and simplifies the drivetrain by making a conventional transmission unnecessary.
Setting a fuel efficiency record
Nearly 30 years after its commercial debut, the Prius remains an icon that combines technological innovation and environmental responsibility. It’s still setting records in fuel efficiency. New in July 2023, the 2024 Prius LE consumed 2.52 liters of gasoline per 100 kilometers during a 5,150-kilometer cross-country trip from Los Angeles to New York. This record was set by so-called hypermilers, drivers who practice advanced driving techniques with the goal of optimizing fuel efficiency. Hypermiller accelerates smoothly and avoids hard braking. They lift off the accelerator pedal early to allow the car to come to a gradual stop without having to apply the brakes, and drive as often as possible at speeds between 72 and 105 kilometers per hour, which is generally the speed at which the car is most efficient.
Drivers without these technologies can still expect fuel economy as high as 4.06 liters per 100 km in the latest generation Prius models.
Toyota has advanced the Prius’ hybrid technology with each generation, solidifying the car’s role as a leader in fuel efficiency and sustainability.
Attracting celebrities through milestone events
Uchiyamada spoke briefly at the IEEE Milestone event about the Prius’ development process and the challenges he faced as a senior G21 engineer. Other notable attendees included Takeshi Uehara, President of Toyota Powertrain Company; Toshio Fukuda, 2020 IEEE President; Isao Shirakawa, Chairman of the History Committee of the IEEE Japan Conference; and Jun Sato, IEEE Nagoya Section Chair.
A plaque recognizing this technology is displayed at the entrance to the Toyota Technology Center, within walking distance of the company’s headquarters. The contents are as follows:
“In 1997, Toyota Motor Corporation developed the Toyota Prius, the world’s first mass-produced hybrid car that uses both an internal combustion engine and two electric motors. This vehicle achieved groundbreaking fuel efficiency by recovering and reusing energy lost during driving. Its success helped popularize hybrid vehicles internationally, advanced technologies essential to electric powertrains, and contributed to CO reduction.2 “It increased emissions and influenced the design of subsequent electric vehicles.”
Administered by the IEEE History Center and supported by donors, the Milestone Program recognizes outstanding technological developments around the world. The IEEE Nagoya Chapter sponsored the nomination.
