Why Don’t Electric Cars Have Transmissions?


If you have ever owned a car with a combustible gas engine, then you are probably well aware of the need for a functioning transmission. Electric vehicles have no such component, leaving many people to wonder why.

Electric cars do not have transmissions because they have no engine. In the place of an engine is an electric motor that produces the exact same torque amount no matter what the RPM is at the time. As such, there are no gears and nothing for a transmission to turn over. 

Transmissions are a necessary part of a combustible gas vehicle, but they can be expensive to maintain and repair. Not having one in an electric car is seen by many as a benefit. Continue reading to discover more reasons why an electric vehicle does not have a transmission and what this can mean for you. 

Transmissions have Several Gears

To better understand why an electric car does not have a need for a transmission, it is helpful first to review the function behind one in the first place. Transmissions are meant to help take the power that is generated from the engine and transfer it to the driveshaft. In turn, this helps to power the rear or front wheels, depending on what type of vehicle it is. 

Transmissions have gears inside of them. Those gears effectively alter the speed and torque at which the wheels turn. This is directly related to the speed of the engine. When the torque gets up too high, the transmission will help shift into another gear to accommodate that added power.

If it were not for a transmission, the power generated by an engine would be capped. There would be no way to turn the wheels any faster. It would also result in an overheated engine. As such, a gas powered car without a transmission is not going to get very far. Aside from the engine, it is one of the most critical parts of such a vehicle. 

Why do Electric Vehicles Use Only One Gear?

Just about every electric car in production today makes use of only one gear. There are quite a few reasons behind this fact. When compared to gas-powered vehicles, for example, the motors in electric cars rev up significantly higher than engines do. Here is a comparison of the two:

  • Electric Motors – Most electric motors will rev up to as much as 20,000 rotations per minute. 
  • Gas-Powered Engines – Most engines that run on gasoline or diesel will only rev up to between 4,000 and 6,000 rotations per minute. 

Because engines do not rev up as high, they need to have gears installed to make up for the difference. It should also be noted that the performance of an electric motor remains consistent no matter the RPM it is running at. It can run just as well at a few thousand RPMs as it can at 20,000. The same cannot be said for combustible gas engines. 

An electric car can get up to its maximum torque very quickly. As such, there is not a specific revolution range that is considered to be optimal. Again, traditional cars need a transmission because there is a difference in performance based upon how many revolutions per minute are evident.

In essence, an electric car only needs one gear because the number of RPMs does not matter. Diesel and gas cars, on the other hand, rely on multiple gears because the engines can only generate a certain amount of torque within a very narrow RPM range. 

Electric cars are also able to reach their top speed quickly and in a single gear. Gas and diesel powered car owners will find that they can only go so fast in first gear before it tops out and must shift into the next gear. The process continues until it reaches its top speed. 

Is There a Benefit to Having Just One Gear?

Now that you know electric vehicles have only one gear, you might wonder what the benefits of this might be. The two most important advantages are:

  • Low cost
  • Simplicity of design

Transmissions are incredibly complex components. Anybody who has ever had to replace a transmission understands just how expensive a proposition that can be. Having just one gear reduces the cost significantly. There is less to maintain and fewer things that can go wrong. 

In addition, just having one gear makes for a simple design. When it comes to electric vehicles, this is a critical benefit. The simpler the design, the less expensive it is on the whole to make. While certain parts of an electric vehicle currently make them a bit more expensive on the whole than their gas-powered counterparts, the absence of gears is not one of them. 

Are Electric Cars Automatic or Manual?

Absent a transmission, virtually every electric vehicle on the road today is automatic. You will not find a clutch. In fact, there is only an accelerator and brake pedal on most models. Some electric vehicles do not even come with a brake pedal. Instead, drivers will learn just to release the accelerator to have the car stop accordingly. 

There is no need to change gears in an electric car. The absence of a transmission means that electric cars are single speed. That should not be taken to mean that such cars cannot go fast, as they can get up to a high rate of speed from a stopped position rather quickly. Instead, single-speed means only one gear.

What is Different About a Car Without a Transmission?

There are some notable design differences in an electric car since it does not have a transmission. The first thing the driver will notice is that there is no gear shifter. In its place, you will just have three options:

  • Park
  • Drive
  • Reverse

This certainly makes it simple to drive. There is nothing more to learn. You do not need to know at which RPM you need to shift into the next gear. There is no shifting that will take place. The only exception will be higher-end vehicles that include driving modes within the design. Even so, there is no transmission to worry about. 

When an electric car accelerates, there are no gears to work its way through. You will notice a constant sound coming from the motor as opposed to the increasingly laborious sound of an engine as the RPMs increase throughout the gear shifting cycle. 

Could Transmissions Be a Part of Electric Vehicles in the Future?

As just alluded to, electric cars are already priced higher than traditional cars. As such, manufacturers will not want to add to that expense without some sort of justification. Given that the technology exists for a single geared electric vehicle to go just as fast as a car that has a transmission, there is no need to have one. 

That is not to say that designers of the future will not try to put in a few extra gears in an electric vehicle. Some have already tried, such as a 2017 Audi electric car model. However, on the whole, transmissions are not likely to be in the future of electric vehicles. 

Wrap-Up 

Since electric vehicles basically run on a single speed, there are no gears to worry about. You simply accelerate and brake to get the car going and to stop it. As such, there is no need for a transmission. The design is simple, making electric cars cheaper and easier on the whole to maintain in comparison to traditional gas-powered vehicles. 

Sources: 

https://www.drivingelectric.com/your-questions-answered/95/do-electric-cars-have-gearboxes#:~:text=There%20are%20many%20reasons%20why,rpm%20limit%20for%20conventional%20cars.

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