Gearbox Options Explained
You are scrolling through Group1cars for your next ride and everything looks great, but what does MT and AT and AMT mean? CVT and DCT? Let’s have a look.
MT stands for manual transmission and was the original way to transfer engine power to the wheels optimally, according to the speed of the car. The driver pushes in the clutch pedal to manually disconnect the transmission from the clutch plate, selects a gear, releases the clutch again to engage the selected gear. Until quite recently this was the most efficient way to change gears, and many drivers still believe it gives the most driver engagement.
All other transmission types are variations of automatic transmission. They are very popular because they remove the clutch pedal and makes driving hassle-free. For many years these were simple gear changing mechanisms that gave sub-optimal performance and poor fuel economy. The latter was not really a problem as fuel used to be very cheap until the early ‘70s.
Since then the automatic transmission has been developed and improved to the point where it usually gives better performance and efficiency than the traditional MT. In the process, several versions of the automatic transmission have seen the light of day. Let’s have a look at them.
AT is automatic transmission and has been around since the early 1920s. It was very popular because it removed the need for the driver to manually do anything to change gears up or down. The AT is also called a torque converter automatic. It uses a hydraulic fluid coupling or a torque converter for changing gears, as opposed to a clutch. The engine control unit (ECU) is directly connected to this and allows the smooth and precise engine control which makes AT so popular.
AMT stands for automated manual transmission. It uses the regular clutch and gear configuration but uses sensors, actuators, processors and pneumatics to stimulate manual gear use. Most AMTs give the driver both fully automatic and sequential manual shift modes. Early AMTs were quite jerky at low speeds, but modern versions are smooth, give great acceleration and very good fuel economy.
CVT stands for continuous variable transmission. This is quite new and does not use traditional steel gears. Instead, it uses belts or pulleys to seamlessly give the optimal ratio based on speed and load. It allows for maximum efficiency and continuous, gear-change-free acceleration, which is good for fuel economy. As with all things radically new, not all petrol head love it. However, enough drivers love the absolute effortless drive CVT gives and more and more manufacturers include CVT as an option. It’s new, so try it before you buy it.
DCT is a dual-clutch transmission. This means it has no torque converter but uses two separate shafts for gear changing, one for odd- and one for even numbered gears. It gives a fast, seamless gear change. DCT is a dry transmission, so it uses no gearbox fluid. Less maintenance, but perhaps a shorter lifespan.
DSG stands for direct shift gearbox and is similar to DCT, but uses a wet transmission. More maintenance, but a longer life.
Tiptronic was developed by Porsche in the ‘90s and is still mostly found in high-performance vehicles. It works like an MT but uses a torque converter in place of a clutch pedal. It gives options for automatic gear shifting and manual selection of gears. There is a feature that prevents the driver from damaging the gearbox through over-revving when downshifting.
We hope this will help you make an informed decision when choosing your next car.
