5 reasons why electric cars have limited top speed
Electric cars are environmentally friendly and have all the convenient driving features, but the top speed of this EV is lower than that of traditional internal combustion engine cars.
In recent years, electric vehicles have gradually become an alternative means of transportation to vehicles using traditional internal combustion engines thanks to their environmental friendliness.
However, the ability of electric vehicles to travel at high speeds is limited, and the maximum speed of electric vehicles is even much lower than that of vehicles using fossil fuels. Here are 5 reasons why.
1. Protect battery life
When it comes to internal combustion engine (ICE) vehicles, the top speed of the vehicle is usually limited by the transmission system and engine oil. But the case of electric vehicles (EV) is different.
Manufacturers aim to make electric vehicles sustainable for everyday commuting. As a result, the top speed of electric vehicles will be limited to keep the battery and circuitry within a certain temperature range.
Because if the maximum speed of the electric vehicle is set higher, the battery will overheat, causing the battery life to degrade faster than the warranty period. The life of an electric vehicle battery is usually 10-15 years.
Additionally, the engine's rpm also plays an important role when considering the top speed of an electric vehicle. For example, Tesla has used a carbon ceramic coating on the moving part to prevent it from contacting and causing friction with the stationary part of the electric motor.
This has allowed the Tesla Model S's engine to reach 20,000 rpm with a limited speed of 260 km/h. However, battery charge conservation is the main reason why electric car manufacturers limit the maximum speed of electric cars.
Studies have shown that if an electric vehicle maintains a speed above 100 km/h, the battery consumption will be 68% higher than when the vehicle is driven at a speed below 50 km/h. This study also confirms that to keep the battery of an electric vehicle in optimal condition, it is best for the driver to adhere to a certain speed limit.
2. Brake protection
If you let an electric car operate at maximum speed, the brakes will wear out and the battery will be depleted in less than 10-12 minutes. The Tesla Model 3 has a speed assist feature so the driver can set a speed limit for the car when driving.
However, there are some limitations such as the driver cannot exceed a set speed or a warning signal will flash on the dashboard. This is to protect the brakes otherwise the system will wear out very quickly.
3. Gear ratio
Gear ratios are essentially the speed at which one gear rotates relative to the others. Electric vehicle manufacturers limit the top speed of their vehicles with gear ratios that produce just enough torque for everyday driving.
This means that electric vehicles will only be able to reach a speed range that is sufficient for daily commuting. This process also affects the acceleration of electric vehicles, but mainly the top speed. Electric vehicles only have a 1-speed gearbox, allowing the engine to have a higher rpm range than other conventional vehicles.
For example a standard ICE car has a rev range of no more than 7,000 rpm while most electric cars can reach 20,000 rpm, as mentioned above.
Some manufacturers have used 2-speed transmissions in electric vehicles, typically the Porsche Taycan and Audi e-Tron GT. In return, 2-speed transmissions add weight to the vehicle and affect the performance of electric vehicles. Many people wonder if electric vehicles have the same transmission as ICE vehicles, but in fact, electric vehicles do not need many gears to operate.
4. Vehicle weight
Horsepower only affects the top speed of a vehicle depending on the gear ratio. But that’s not the only limiting factor when it comes to the top speed of an electric vehicle, as the aerodynamics and weight of an electric vehicle can also affect its top speed.
If we consider the aerodynamic drag of electric vehicles, the drag will increase every time the vehicle accelerates, which affects the charging of the electric vehicle battery. The weight of electric vehicles is usually heavier than that of gasoline vehicles, mainly due to the battery pack and the battery protection frame, making it difficult for the vehicle to operate at higher speeds.
Another reason why electric cars don’t have high acceleration is because of the simplicity of the technology. If you put a lot of complex technology into an electric car to reach a high top speed, it will make the electric car less durable for daily driving.
For example, a complex inverter would provide the precise voltage needed to operate an electric car at higher speeds, which would not only increase the cost of the electric car but also make it more expensive.
However, electric vehicle manufacturers are now focusing on the range and safety of electric vehicles rather than acceleration. Because for a new form of transportation like electric vehicles, consumers still need to look for safe models rather than fast ones.
5. Safety
As mentioned above, in order to make electric vehicles safer to drive, automakers rarely focus on the speed and acceleration of electric vehicles.
Most potential consumers prefer to drive at moderate speeds and need the ability to travel long distances, which means that if the electric vehicle industry focuses more on acceleration and higher top speeds, they will have a hard time selling cars.
Moderate speed not only increases the safety of electric vehicles, but also makes the battery of electric vehicles last longer. Moreover, only fully charged electric vehicles can deliver maximum power.
In short, the safety of the driver and other road users is the main reason why automakers do not add a complex system to increase the top speed of electric vehicles.