Kinetic energy? While braking, the Prius makes a peculiar mechanical sound similar to an anti-lock braking system being exercised to its maximum. The motor functions as a generator which turns the kinetic energy from the wheels into electricity to charge the battery. This makes the Prius one of the first vehicles to be more efficient in city than in highway driving.
Toyota has created a planetary gear system that swaps the gasoline engine with the electric, by having one gear power the wheels while the other is driving the generator. A shaft from the motor delivers outward power via pinion gears, to the outer ring gear and inward to a sun gear. The wheels are driven through a drive shaft that is attached to a ring gear shaft. The sun gear shaft drives the generator. While it sounds complicated, the entire process is seamless. Just put in the key, slip it in drive, accelerate and steer.
The 1.5-liter gasoline engine is hardly conventional either. Its combustion chamber volume increases the expansion ratio and extracts energy more effectively. The engineers retarded the shutting of the intake valves, reducing cylinder pressure and eliminating knocking. As well, engine revs are kept to a minimal 4,000 rpm so that smaller, lighter components could be used.
What is the result of Toyota's mastermind engineers? How about 28km/L (77 mpg) in the city? That equals 1,000 km (621 miles) to a (45-liter/11.9 gallon) tank of gas. What's more the Prius produces 50% of the carbon dioxide a conventional gasoline powered vehicle does, and around 10% the CO, HC and NOx of Japanese legal requirements. It also meets California's Super Low Emission Vehicle (SULEV) standards.
Toyota has created a planetary gear system that swaps the gasoline engine with the electric, by having one gear power the wheels while the other is driving the generator. A shaft from the motor delivers outward power via pinion gears, to the outer ring gear and inward to a sun gear. The wheels are driven through a drive shaft that is attached to a ring gear shaft. The sun gear shaft drives the generator. While it sounds complicated, the entire process is seamless. Just put in the key, slip it in drive, accelerate and steer.
The 1.5-liter gasoline engine is hardly conventional either. Its combustion chamber volume increases the expansion ratio and extracts energy more effectively. The engineers retarded the shutting of the intake valves, reducing cylinder pressure and eliminating knocking. As well, engine revs are kept to a minimal 4,000 rpm so that smaller, lighter components could be used.
What is the result of Toyota's mastermind engineers? How about 28km/L (77 mpg) in the city? That equals 1,000 km (621 miles) to a (45-liter/11.9 gallon) tank of gas. What's more the Prius produces 50% of the carbon dioxide a conventional gasoline powered vehicle does, and around 10% the CO, HC and NOx of Japanese legal requirements. It also meets California's Super Low Emission Vehicle (SULEV) standards.