There’s been a huge push to electric vehicles in recent times. While they’re just a small percentage on the road, we can expect to see more of them as countries like the UK ban the sale of new petrol and diesel cars by 2030.
For many people, understanding how an electric car works is essential.
You will remember the manual car from yesteryears as having three gears while the modern internal combustion engine (ICE) car has six gears. This is because an ICE car is efficient within a specific range of rotation speed. That’s why it needs gears to deliver the ideal power over a wide range of speeds.
However, an electric car can deliver full torque at zero RPM. It does not require different gear ratios meaning if the engine is at a certain RPM, the wheels will turn at the same value. It is not something you can change. It comes as a fixed value for the car from the manufacturer.
Why don’t Electric Cars use Gearboxes?
Except for models produced to maintain normality for drivers, you won’t find a gear stick in an electric vehicle. The brushless AC motor can produce enough torque without compromising low-speed driving.
Besides, an electric vehicle does not have a minimum running speed. To need a low gear would mean multiplying the starting torque should it be insufficient. It’s no wonder an electric vehicle can rev four times higher than an internal combustion engine car. We are talking 20,000 RPM in an EV compared to 4,000-6,000 RPM in an ICE car.
Instead of a gear stick, you will find buttons or switches like ‘drive,’ ‘park,’ ‘reverse,’ and ‘neutral.’ Sportier EVs have more modes that change the way the car drives. In the Porsche Taycan, there are five driving modes, including Range, Normal, Individual, Sport, and Sport Plus.
Why do Some Electric Vehicles have Traditional Gear Transmission?
EVs don’t need gearboxes because the highest torque is available at zero RPM, but the torque decreases as the RPM increases. That’s why formula E race cars use gearboxes. It gives the vehicle more usability at high cruising. The Tesla Roadster and Porsche Taycan two-speed gear box gives these cars the ability to push beyond the top speed cap.
Advantages of Automatic Electric Cars
There are benefits to the lack of gears and a clutch in an electric vehicle. The weight of transmission could hinder speed in an EV. That’s why manufacturers don’t view it as an option for normality purposes.
1. Low Cost of Production
An electric vehicle does not come cheap. Add that to the cost of full transmission, and an EV would be out of reach for many. The complexity of a clutch system also adds to the production cost, which would make the electric vehicle less favorable.
2. Inexpensive to Repair and Maintain
The lack of multiple gears in an electric car means fewer parts are moving around. You don’t have to keep the vehicle in its happy zone, so there’s no risk of damaging the vehicle if you compromise between acceleration and top speed. It’s one of the reasons why maintaining an electric vehicle is easy.
3. Instant Power
An electric motor delivers its highest torque at low RPM. It does not require a system to disconnect the engine from the drivetrain to idle when the vehicle is stopped. When you start the engine, the single gear transmission sends maximum torque from the engine to the wheels.
On the other hand, a gas engine reaches its highest power at the top end of the rev range. It loses power when heating the components involved in accelerating the car. Because an EV has few moving parts it delivers most of its horsepower to the wheels instead of the transmission first. It’s the reason why electric supercars like Tesla can go from 0-60mph in 2.3 seconds.
Easier to Drive an Electric Car
Most people who are out of driving practice will like how convenient it is to drive an electric car. One, you don’t have to remember when to use the gear at different road speeds. The absence of the clutch means that the car will not stall when you forget to gear down.
Disadvantages of Automatic Electric Vehicles
1. The Lost Thrill of the Engine Roar
Lovers of sports cars will tell you they live for the vroom. It’s such a satisfying sound that only an ICE car can provide. Electric motors are silent, which means the cabin is also quiet. Some say the silence in an EV is eerie, especially because you can’t match the acceleration to any sound the car is making.
Some manufacturers have tried to match this sound using a stereo in the cabin, but it’s not comparable to the real thing.
2. Lacks the Pull of the Engine
While electric cars can reach high speeds, maintaining them does not mean you will feel the engine working. The vehicle is refined in that it works at a set speed and power ratio. In a gas vehicle, you can feel the engine reach its max speed and power as it keeps the vehicle cruising at the selected speed.
3. Striking Different from an ICE Car
Driving an electric car for the first time will feel different. You will have to adapt to instant acceleration without listening to the little explosions an instant combustion engine car produces when the motor is blowing up petrol. You also don’t need to coordinate between shifting the gear and using the clutch, which is what driving is all about.
Can Electric Car Use Manual Transmission?
This question stems from Renault’s Formula E racers having a two-speed gearbox. While these cars have a manual gear shift, they don’t feature a clutch. The gear shift is solely for managing driving at high speed.
It’s not logical to have a traditional transmission system in a standard, mass-produced electric car. The car would lose its efficiency to accelerate fast since it would lose power as it goes through the transmission system.
Even so, an electric vehicle can’t stall, eliminating the need for a clutch. Adding a manual gearbox and clutch can be done by enthusiasts to cater to the need to row through gears while driving.
Conclusion
An electric car does not have a clutch, a manual gearbox, torque converter, or automatic gearbox. It is automatic because it has a simple drivetrain that delivers power directly to the wheels. The electric car’s ability to produce consistent torque at any given RPM eliminates the need for a gearbox. Hence, the reason why we say an electric car is automatic.
Sam is Automole’s editor-in-chief and classic car enthusiast. Sam is studying mechanical engineering at Cockrell School of Engineering, Austin. He also writes for many top automotive publications and appears on the Collecting Cars Podcast.