German manufacturing company Schaeffler ran its own Step2 electric car in the Silvretta E-Car Rally in Austria. The car is a Volkswagen Golf, stripped of its internal combustion guts and equipped with an electric powertrain supplied by one of Schaeffler's subsidiaries. The thing that makes the Step2 a little different, though, is the inclusion of a two-speed transmission.
Tesla Motors famously started with a two-speed transmission but then ditched that strategy and today most electric cars use a single gear to transfer power from the motor to the wheels, and have no problems with drivability thanks to a relatively flat torque curve. This is great: smooth, comfortable driving, no costly transmission maintenance, no waiting for power while shifting, no added weight from the bulky gearbox. Plus, it's not ludicrous to think that including the unnecessary transmission with multiple gears would be less efficient due to mechanical losses. But Schaeffler is re-thinking the status quo.
Most electric cars use a single gear to transfer power from the motor to the wheels, but Schaeffler is re-thinking the status quo.
In the E-Car Rally, the goal is not to complete the course in the least amount of time, but rather using the least amount of energy, and the alpine driving event allowed Schaeffler to put the Step2 to the test. The rally, as well as other driving tests and simulations, has shown that by using the two-speed transmission with a low and high ratio, the car is actually more efficient. The group reports the gearbox-equipped Step2 reduces energy consumption by about six percent.
With greater efficiency, obviously, the car also can drive farther on a single charge. Shaeffler's vice president of automotive research and development, Uwe Wagner, says, "With a two-speed gearshift system, a low ratio for high tractive force and a high ratio for good overall efficiency also at high driving speeds, we offer higher dynamics and at the same time we achieve a longer range of electric operation."
The Step2 sounds like a fairly simple conversion from a standard internal combustion car. Beyond replacing the powertrain, fuel tank and exhaust system with an electric motor, battery and the two-speed transmission, little else was changed. Schaeffler modified the front axle, but left the steering and brakes alone. No regenerative braking to boost the efficiency numbers here. In terms of power, its output peaks at 70 kilowatts (about 94 horsepower), with 50 kilowatts (67 horsepower) offered in continuous operation. Learn more about Schaeffler's Step2 in the press release, below.