Eaton and BAE collaborate on medium- and heavy-duty electric powertrain with a 4-speed transmission
Like golf carts, most electric cars have a single gear. There are currently only two EV models with more than one gear, the Porsche Taycan and the Audi e-tron GT, which both have two. Porsche says the reason behind the two-gear Taycan is to ensure “high efficiency and power reserves even at very high speeds.” That second gear isn’t at all necessary, but does it offer its owner a bit more confidence in the luxury performance vehicle’s power? Likely.
For drivers of electric consumer vehicles, that power boost could come in handy for drivers of medium- and heavy-duty commercial vehicles that haul significant weight.
Volvo equipped its VNR, a Class 8 electric truck, with two gears. The Freightliner eCascadia also features two speeds. However, Tesla opted for a single gear in its Tesla Semi, albeit with three different motors powering the wheels. On the medium-duty side, Freightliner also equipped its eM2 with a 2-speed transmission. While these vehicles can meet some industry needs, Eaton and BAE have found the benefit of putting traditional transmissions back into EVs—with some modifications, of course—and the whole system appears less complicated than EVs with no transmission.
“Both [Eaton and BAE] realized there’s a benefit to having a multi-speed transmission in some, but not all, applications,” Justin Hopkins, product director, E-Powertrain, Eaton said. “When you are getting into some of these heavier applications where you need a strong startability for when it’s going up a high grade—20, 25, 30%—and you also need to operate the vehicle at 60-65 mph on the highway efficiently, having a multi-speed transmission better enables you to go to a smaller, lower-cost motor.”
