Hello Guys today I will explain why electric cars have only one gear. That does not mean there are no gears in electric cars.
Electric cars are getting popular day by day. With Tesla taking electric cars to different level, there are other car companies also building electric cars. Surely in india it will take time for electric cars to get in market.
Why do Electric cars have one Gear?
- The main reason is high revving electric motor. Electric motors can rev around 10000 rpm in a normal daily running electric car, which is very high compared to an internal combustion engine.
- The power is efficiently spread across a broad rpm range.
- High torque generation at low rpm. Low as 0 rpm.
- Also having a transmission means putting more weight and more complexity and it will lose its efficiency.
Electric motor can be geared specifically for that top speed. But when compared to electric car, gasoline engine need multiple gears to reach the top speed. All electric car are set at different top speed. The normal road electric cars are limited to 160 kmph.
Some electric cars have a couple of gears. In formula E 3 speed car was used. So what is benefit of having gears.
In formula E the power is limited to 170 KW. Power increases gradually to the limit, but at low-speed the power is not completely used which decreases the acceleration. To overcome the low acceleration this electric cars use gears. Because more aggressive gear will spin the wheel faster and you will have more wheel torque. You will reach the peak power faster when compared to single gear electric motor.
It also depends on the size of the electric motor and the torque it is generating. Smaller motor with low torque will have advantage with multiple gears. Whereas big electric motors with higher torque can do better with single gear.
Watch this video by Engineering Explained, he explains it beautifully. He has made this video in partnership with formula E.