Tag Archives: transmission

EV

Multiple-speed transmission for EV: necessary or not?

The transmission, or gearbox, is one of the crucial components in a vehicle to ensure that every horsepower produced by the engine can be effectively transmitted to the road.

This is because internal combustion engines (ICE) can only generate efficient power within certain engine speed ranges, and each speed ratio is calculated and specified according to the engine output by manufacturers to maximize efficient power delivery in each gear.

It’s a different story for EVs.

Unlike ICE, electric motors can consistently generate maximum instantaneous power at any RPM range.

It can be said that most EVs in the market have a single-speed transmission, where the gear ratio has been meticulously calculated to maximize the efficiency of the electric motor.

Due to the already efficient operating system, most manufacturers believe that the use of multiple-speed transmissions will only add inefficiency, such as increased weight and production costs.

However, there are premium EV models like the Porsche Taycan that use a two-speed gearbox.

The first gear is designed to maximize acceleration, while the second gear ratio is designed to ensure efficiency and high power reserves even at high speeds.

Formula E racing cars even have three-speed transmissions!

So, what about certain manufacturers like Hyundai and Toyota?

Hyundai introduced the N e-shift feature, allowing drivers to simulate gear changes as if using an 8-speed DCT transmission in the Ioniq 5 N model.

Toyota, on the other hand, experimented by fitting a manual gearbox to the AE86 BEV model, complete with a foot clutch!

All of these efforts are made to ensure that the art of driving and manual gear changes will not disappear even when the world fully transitions to EVs one day.

TIPS

Beginner’s guide to types of automatic transmission

It cannot be denied that driving a manual car provides a satisfaction that is sometimes hard to put into words. With the ability to row your own gears at any time, a manual transmission will give you a sense of control, enjoyment, and freedom.

However, with the advancement of technology and the increasingly heavier traffic conditions especially in urban areas, automatic transmission seems a more sensible option for daily use. Not only is it easier to operate, but modern AT is generally able to change gears quicker and more smoothly.

Did you know that there are several types of automatic transmissions used in modern cars? Let’s take a look:

Torque Converter

This is the most common conventional automatic transmission found in cars. The torque converter refers to the device used to transmit power from the engine to the gearbox and then to the wheels.

Unlike mechanical clutches with a physical connection, it uses a dense hydraulic fluid to ensure power (or torque) from the engine to the gearbox. It’s this fluid that allows for smooth gear changes.

In the past, this type of transmission was not very efficient in terms of power delivery, but thanks to continuous research and development from manufacturers, modern versions on the market today are much better.

Dual-Clutch Transmission (DCT)

Dual-clutch transmission, or DCT, was first introduced through the Volkswagen Golf R32 in 2003. As the name suggests, it uses two clutches, one for even gears (2,4,6, and so on) and another for odd gears (1,3,5,7, and so on).

Why? To enable faster shift times, of course. For instance, if you are accelerating in fourth gear, the gearbox will line up the other clutch in preparation to shift to fifth gear. The same goes if you’re slowing down. If you are braking in fourth gear, it will be ready to downshift to third.

This allows the DCT to shift gears quickly, whether you are accelerating or decelerating. However, it tends to be jerky, especially when the car is moving at low speeds.

Continuously Variable Transmission (CVT)

Among the most talked-about transmissions today, CVT uses a pair of cone-shaped pulleys – one connected to the engine and the other to the driveshaft. The pulleys are connected to one another by a belt.

This gives the CVT an infinite gear ratio, allowing the engine to remain in the power band (the range of operating speeds under which the engine generates the most power) when you step on the accelerator pedal.

This results in powerful and smooth accelerations, but at the same time, a CVT can be rather noisy to the point that it affects the driving experience.

Automated Manual Transmission (AMT)

Also known as semi-automatic or robotised manual gearbox, AMT works and has similar mechanisms to the manual transmission but the clutch is operated through electrohydraulic means using actuators, sensors, and more.

This means that AMT offers the convenience of a conventional automatic gearbox while allowing the driver to shift gears manually if they wish.

This type of transmission became popular in the 90s and early 2000s thanks to high-performance cars like the Ferrari 355 and BMW M3. However, it’s infamous for being jerky when changing gears.