FRANKFURT, Germany—With hybrid vehicles still in their relative infancy, Toyota is looking to show the green technology has a mean side with the debut of its Yaris Hybrid-R concept at this month’s Frankfurt auto show.
Powered by a punch-packing 300-horsepower turbocharged 1.6-litre engine and a pair of 60-hp electric motors, the subcompact Hybrid-R was designed to deliver maximum driveability on the road and the race track.
According to the automaker, the Hybrid-R gets power to the front wheels through the high-output four-cylinder engine, with the twin 60-hp electric motors—the same ones used in the standard Yaris Hybrid—powering each rear wheel, providing what Toyota calls “intelligent electric four-wheel drive capability.”
The entire hybrid powertrain system develops a total system output of 420-hp, with the two electric motors working as electric generators during the braking phase, and supplementing the gasoline engine during the accelerating phases.
Just like in Toyota’s TS030 HYBRID race car, which participated at Le Mans and in the World Endurance Championship, the energy recovered during the braking phase is stored in a super capacitor.
In the Yaris Hybrid-R, the super capacitor is located under the rear seat, where the Yaris Hybrid battery is usually positioned.
Toyota says compared to the standard NiMh hybrid battery, the super capacitor has a higher power density and a fast power charge and discharge speed.
A third 60-hp electric motor, located between the engine and the six-speed sequential transmission, operates as a generator in two different cases: during deceleration to feed the super capacitor and during acceleration to directly power the rear electric motors.
The latter will only happen when the engine power and torque exceed the grip potential of the front wheels, acting as a traction control system, of sorts, that redirects torque to the rear wheels to improve handling and acceleration.
One of the coolest features of the Hybrid-R is its so-called “track mode,” where engine and electric motor output is maximized to 300-hp and 310 lb.-ft. of torque at the front wheels and a combined 120-hp at the rear wheels for as long as five seconds at a time.
At low speeds, or in a curve, when the engine power and torque exceed the grip potential of the front wheels, the third electric motor kicks in as a traction control system, redirecting the gasoline engine’s extra torque as electric energy to the rear wheels.
Toyota says the Yaris stays true to its traditionally tame hybrid roots in “road mode,” with engine output dropped—including a drop in the turbo system’s maximum boost of 36.3 psi greatly reduced.
The super capacitor can release the energy recovered under braking for a maximum duration of 10 seconds as opposed to the five seconds in track mode, while the total power of the two electric motors is limited to 40-hp.
The third electric motor can also be used at any time as a generator.
Much like all concept cars, it’s highly doubtful that the Yaris Hybrid-R ever makes it to production.
But if even a little of its DNA works its way into showrooms one day Toyota may have found the recipe to make hybrid technology cool.