Why Do Electric Cars Have A Low Top Speed? Or Do They…?

Electric cars have taken us into the future via their cutting-edge technology, and they often come with many additional features that gas-powered vehicles just don’t have.

However, one common question asked about EVs is “why do electric cars have such a low top speed for the amount of horsepower they have?”

The top speed of an electric vehicle seems low for its horsepower mainly because of the gearing used by vehicle manufacturers, which ensures they are suitable for daily use.

The manufacturers limit the top speed in EVs through their 1-gear gearbox to preserve battery charge, as when a high cruising speed is maintained, more energy is consumed.   

This article will discuss why electric vehicles have such a low speed when compared to their high horsepower.

So keep reading! We have everything you need to know about why electric cars have low top speeds.

How Much Horsepower Is In Your Average EV

While it may seem that the majority of electric cars have a greater amount of horsepower when compared to gas-powered vehicles, this isn’t always the case.

Sure, the Tesla Model S Plaid has around 1020 horsepower, and a BMW 3 series has as little as 255, but this is just a special case. 

An electric vehicle such as the Tesla Model 3 Long Range has a combined horsepower of 480.

This is derived from two motors, one in the back averaging 283 hp and a motor in the front providing 197 hp. This will provide the car with a top speed of around 140mph. 

Whereas an Audi A4 that has around 190hp will be able to reach 150 mph with a lot less horsepower than the Tesla Model 3.

So even though the Tesla Model 3 has much greater horsepower and acceleration rate, it still cannot outrun the Audi A4

In most cases, it all depends on the motor size of the electric vehicle. For the most part, when it comes down to what gives electric vehicles an advantage over gas-powered cars, it’s their acceleration.

You will notice that EVs have instant torque, which provides a vast difference between EVs and gas-powered cars.

Why Do Electric Cars Have Such High Horsepower?

There are a few reasons as to why some of the higher quality electric vehicles, such as the Tesla range, have an enormous amount of horsepower.

For one, electric cars have a much better power efficiency, resulting in about 90%.

This means that 90% of the power produced from the battery and transferred to the motor is isolated and available for us, i.e., it doesn’t suffer from processes such as heat loss.

At the same time, a gas-powered vehicle may only reach a maximum energy output of around 40%.

As a result, when driving a gas-powered vehicle, you’ll only get around 40% of the potential energy, as the majority is lost due to heat and friction within the moving parts.

As a result, you will only get a fraction of the potential horsepower, whereas electric vehicles get 90% of their possible horsepower.

Electric motors usually have a lot more torque when compared to vehicles that run on has, and this torque in EVs is produced throughout most of their RPM range.

Thus, more horsepower is basically the result of a high torque multiplied by its RPM. 

Do Electric Cars Really Have A Low Top Speed?

Electric vehicles have a much faster rate of acceleration when compared to the majority of gas-powered cars.

This is because an electric vehicle can provide full torque, i.e., the force that drives the car forward. 

The reasoning behind the electric cars’ low top speed when compared to their horsepower can be justified by their gearbox.

As electric vehicles only have one gear, it means that a sacrifice had to occur, which would either affect the acceleration or top speed.

A high gear would make it difficult to get started, as it only has one gear, whereas a low gear would mean greater acceleration but a lower top speed.

Most electric vehicles meet in the middle of this scenario and provide outstanding acceleration, torque, and average top speed for their horsepower.  

All electric cars run on AC motors, and as the speed of an EV’s motor increases, the frequency and electromotive force or EMF, commonly called voltage, must also increase to keep the torque constant. 

If the frequency and EMF are not increased in proportion to speed, this will decrease the overall power and torque of the car as a higher speed is achieved.

Thus, as the vehicle edges towards its maximum speed with the available EMF, the power will decrease long before the car reaches its top speed. 

Manufacturers realized that when they were creating electric cars, the gearbox could only sustain a greater acceleration or top speed.

So, an EV with 300hp at a particular speed could not go any higher than this because the EMF could no longer be increased.

Thus, electric cars have a low top speed if you compare them to their horsepower.

Can Future Technology Increase An EV’s Top Speed?

While most electric cars have a top speed that is entirely sufficient for everyday use, whether driving around town or the highways, a commonly asked question is, could they eventually reach a top speed that would compliment their high horsepower?

One of the most common ideas is that you can create a 2-gear gearbox, yet Tesla ran into this trouble with the Tesla Roadster.

This would balance out the acceleration rate with the higher top speed. 

Other manufacturers have realized that two of the main issues holding back the speed of electric vehicles are the battery capabilities and the car’s overall weight. 

While manufacturers are slowly reducing the weight of EVs through the use of aluminum, they still have a long way to go before it will dramatically increase the speed of the car. 

Whereas battery technology is a better idea, as this is something that can be improved over a short period.

The idea is that a lighter battery, which provides more power, is how manufacturers will be able to increase the top speed of an electric vehicle.