Easy driving is developing before us at a surprisingly rapid rate. We’re loving what Apple CarPlay, safety assistants and satellite navigation can do for our driving comfort, and an automatic gearbox is an addition we can’t complain about. But do you know there are many types of automatic gearboxes? Are you looking for smooth driving, efficiency, or affordability? Read on to find out the types of automatic gearboxes, which one is best for you, and the best automatic cars!
The gearbox matches the speed of the engine to the speed of the car. The problem is car engines develop their power differently depending on the speed they are travelling at. It’s the role of the gearbox to match the speed of the engine to the speed of the car within a suitable range of useful torque. Failing to do this means the engine will either choke or produce high revs. A gearbox uses different combinations of gear wheels to be selected so that the engine is operating at a speed that can handle the speed of the car.
Changing gear is simply switching from one combination of gear wheels to another so that the engine can produce an optimal torque at a given car speed. This requires the engine to be momentarily disconnected from the rest of the car (axels, wheels, etc.) and readjusted to a new gear ratio. Manual gearboxes require your foot to press the clutch to make the disconnect and your gearstick to choose a new gear ratio. Automatics don’t require a separate clutch system and use pressurized fluid to transfer power to the gear selection where sensors recognise when it’s time to shift up or down a gear.
Automatic transmissions benefit from great reliability, lower wear and tear on driver and car, better hill starts and greater control of gears. There are seven types of automatic transmissions: Torque Converter, CVT, AMT, Dual Clutch Transmission, Multi-Clutch Transmission, iMT and Electric. Let’s go through each below.
Torque Converter. These are some of the oldest and most robust automatics around, built to reliably cover thousands of miles without ever breaking a sweat. Torque converters are perfect for high torque engines, using hydraulics to change gears and fitted with a nice smoothness in recent years. Typically containing 6 to 10 gears, torque converters are usually found on luxury or powerful cars.
This makes torque converters great if you want power for towing or you’re just generally looking for high torque. They are also great if you want a long-lasting and low-demanding system on your vehicle.
CVT. A Continuously Variable Transmission is one of the most widely used automatic transmissions today. Its popularity derives from its easy-to-drive function and smooth, linear throttle inputs. Rather than using a series of cogs for the gears, CVTs use belts and cones. This unique system allows the most efficient gear to be selected with consistent accuracy. Despite these benefits, many are hesitant to use CVT automatics due to their strange noise while driving, where rather than the engine rising and dropping following the gear changes, the noise instead continually rises as the speed increases.
If you are looking for an automatic with a great deal of smoothness and fuel efficiency, a CVT transmission might be exactly what you are looking for.
AMT. Automated Manual Transmissions use an automatic clutch and gear shifter on a regular manual system. AMTs are beneficial in that they have the option to return to fully manual operation. Because AMTs are modified manual transmissions, their simplicity makes them affordable to produce and repair. They are typically found in smaller, less expensive cars. Their fuel efficiency is of note too, but their smoothness is compromised as the gear changes remain, in essence, as a manual system.
This makes AMTs great for first-time buyers who are looking for an easy transition to automatic driving or are simply looking for a more affordable option.
DCT. A Dual Clutch Transmission is an advanced transmission system that uses two clutches. One clutch engages with the current gear while the second is already primed to select the next gear. This allows for incredibly quick and effective gear changes. Additionally, the time saved between switching gears subsequently leads to improved fuel efficiency. We see DCTs on most high-performance cars because the drag and idling losses are minimised.
To some, this system is not ideal as drivability is something to get used to due to the reduction in smoothness. However, for those looking for an automatic system that prioritises high performance, speed and acceleration, a DCT might be for you.
Multi-Clutch Transmission. The MCT is a recent advancement of automatic technology which employs a “clutch pack” that is controlled separately instead of a torque converter. The MCT is differentiated from DCT because of its single input shaft. The benefits of MCTs are that they can handle high torque while not occupying a great deal of space under the bonnet. Their reaction times are high and the multi-clutch operation creates an incredibly smooth drive.
iMT. This is an intelligent Manual Transmission system. Here, the clutch is controlled automatically while the gear shifts are done manually. This is like an AMT, but less automated. This makes iMTs the most affordable automatic system as only a few components are required to fully automate the clutch control. iMTs are smooth to drive and lie on the boundary between automatic and manual systems.
Electric. Of course, one other automatic car system remains and that is the EV. While technically without a gearbox entirely, EVs typically have a lever to switch between drive and reverse settings. Some EVs simply spin the motor backwards to achieve a reverse setting, while others have a separate motor entirely. These are classified as automatics since, like iMTs, they drive without a clutch pedal. EVs produce torque from the motor and don’t require it to be matched to the speed of the car.
Since no gears are present and the speed of the car is consistently matched with the speed of the engine, EVs are technically the smoothest automatic drive. Pay attention to your EV battery range when towing heavy loads as, just with a combustion engine, the efficiency will decrease.
By now, you might have a pretty good idea of what type of automatic you want. We’ve given a few examples below of some cars that use their automatic system excellently, because when we ask for the ‘best automatic’, we’re looking for the most reliable torque converter, the smoothest CVT, or the best performing DCT (and so on).
Torque Converter. Mazda is very consistent with the quality of their engines across their fleet, and their automatics don’t stray away from this. The Mazda2 is a prime example of a vehicle that employs a quality torque converter, producing smooth shifting and predictably reliable nature. Again, torque converters are the most tried and tested automatic systems; and the Mazda2 retains a competitive edge over more modern automatic designs on the merits of dependability, handling and driving comfort.
Multi-Clutch Transmission. As we know, MCTs are perfect for our high torque and smooth driving needs. The Mazda CX-60 redefines what we understand about these benefits. With an 8-speed automatic transmission that integrates with an electric motor, the CX-60 gains a fast and rhythmic shifting feel where the electric motor fills in the drops in power between gear shifts, producing a powerful, linear acceleration. A higher automatic torque also grants the CX-60 a greater towing capacity, supporting up to 2500kg!
DCT. When we look at dual-clutch transmissions, we expect a car with a sporty, high-performance attitude and a good deal of efficiency. We’d suggest the Hyundai i30N. The 2.0T turbocharged engine exudes power that is kept under control by the wet-type 8-speed DCT with paddle shifters. Even with the automatic transmission, you can still connect to the racer feel with a shift lever, and while you’re there, select ‘N’ mode to bring the powertrain and chassis to their highest performance settings.
Electric Motor. It’s a bit sneaky of us to put an EV in an automatic list, but it’s hard to disagree that they both lack a clutch and use the same basic gear shift design. Either way, you won’t be disappointed when driving the Hyundai IONIQ 5. Its solid steering meets a smooth driving experience to give you a good feel of the road without the engine ever needing to catch up to your inputs. The powerful electric motor can boast a range of up to 315 miles of smooth, composed driving too. It’s no surprise why this next-level EV has won so many awards – why not find out for yourself?