The above are a bunch of letters that all relate to transmissions. CVT, as you may know, stands for Continuously Variable Transmission; DCT, you may not know. It's short for Dual Clutch Transmission.
Without going into all the details about how each transmission works, I can say that the CVT is a fairly simple device with few moving elements, while the DCT is a highly complex gizmo with many parts. A CVT has no gears. A DCT will usually have six or seven.
CVTs have been around for decades and it's no secret as to why: fewer parts typically mean fewer headaches and lower build costs for the manufacturer. The problem early on was that reliability was not the CVT's forte. They all but disappeared in the '90s, but made a comeback in the early 21st Century with Nissan, in particular.
CVTs were, and are, often frowned upon by most that enjoy driving, as all they do is wedge engine rpm against the redline when accelerating hard. In a buzzy 4-cylinder car, this ain't no fun. Nissan has more or less perfected the art, and their Xtronic works well. CVTs are also recognized as being a good ally to fuel economy. Some manufacturers program gears (read: preset ratios) that can be selected manually, but any which way you slice it, the 'box is boring and often slow to react.
IMO, they were necessary. Why? As a temporary stopgap measure between typical automatics and the future of transmissions: the DCT.
DCTs are the bomb. Here's the most concise way I can explain how these technological marvels function: The gears, including reverse, are split onto two shafts. Each shaft has its own clutch which is always preselected by the computer for either a down- or an upshift. When you're in “D” (whether in automatic mode or if you decide to select gears on your own) the cog swaps occur in milliseconds, putting a stop to shift-shock as well as any interruption in power delivery.
Most cars equipped with these transmissions also get wheel-mounted paddles (aka flappy paddles). Given rapid shift speeds and immediate input responses, these boxes are a joy to manhandle. In some cases (such as Porsche's PDK), the mechanism is so good that it does a far better job than the vast majority of drivers and so-called pilots.
The other advantage to the DCT is that it does away with torque converters, a crucial element in automatic transmissions. The absence of this piece allows for carmakers to set up cars with start-stop technology, a future must-have to put an end to needless idling.
The downside is that it will most likely signify the end of the conventional manual gearbox. This saddens me to no end, but I will get over it.
Have you tried a car with a DCT? Do you like it?
Without going into all the details about how each transmission works, I can say that the CVT is a fairly simple device with few moving elements, while the DCT is a highly complex gizmo with many parts. A CVT has no gears. A DCT will usually have six or seven.
CVTs have been around for decades and it's no secret as to why: fewer parts typically mean fewer headaches and lower build costs for the manufacturer. The problem early on was that reliability was not the CVT's forte. They all but disappeared in the '90s, but made a comeback in the early 21st Century with Nissan, in particular.
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| CVT (Photo: Nissan) |
CVTs were, and are, often frowned upon by most that enjoy driving, as all they do is wedge engine rpm against the redline when accelerating hard. In a buzzy 4-cylinder car, this ain't no fun. Nissan has more or less perfected the art, and their Xtronic works well. CVTs are also recognized as being a good ally to fuel economy. Some manufacturers program gears (read: preset ratios) that can be selected manually, but any which way you slice it, the 'box is boring and often slow to react.
IMO, they were necessary. Why? As a temporary stopgap measure between typical automatics and the future of transmissions: the DCT.
 |
| DCT (Photo: Porsche) |
DCTs are the bomb. Here's the most concise way I can explain how these technological marvels function: The gears, including reverse, are split onto two shafts. Each shaft has its own clutch which is always preselected by the computer for either a down- or an upshift. When you're in “D” (whether in automatic mode or if you decide to select gears on your own) the cog swaps occur in milliseconds, putting a stop to shift-shock as well as any interruption in power delivery.
Most cars equipped with these transmissions also get wheel-mounted paddles (aka flappy paddles). Given rapid shift speeds and immediate input responses, these boxes are a joy to manhandle. In some cases (such as Porsche's PDK), the mechanism is so good that it does a far better job than the vast majority of drivers and so-called pilots.
The other advantage to the DCT is that it does away with torque converters, a crucial element in automatic transmissions. The absence of this piece allows for carmakers to set up cars with start-stop technology, a future must-have to put an end to needless idling.
The downside is that it will most likely signify the end of the conventional manual gearbox. This saddens me to no end, but I will get over it.
Have you tried a car with a DCT? Do you like it?