When it comes to cars, many people prefer powertrain selections, and for good reason. Vehicles today are equipped with manual or automatic transmissions for different drivers.
With automotive advancements came dual clutch transmissions, which are drastically different from traditional automatic transmissions. From Porsche’s PDK system to VW/Audi’s DSG, it’s clear that dual clutch transmissions are better, but why?
What is a DCT?
DCT stands for dual clutch transmission, which is also representative of the construction. Traditional automatic transmissions use torque converters and gears to operate, while DCTs use two clutches instead of one. Therefore, they are commonly known as Automated Manual Transmissions (AMTs).
The two-clutch system in a DCT transmission is what really sets it apart from a traditional automatic transmission. DCTs don’t work on their own like those transmissions with torque converters, forcing the car to roll back on hills like a manual transmission. Unlike manual transmissions, DCTs have impeccable shifting ability in terms of timing and consistency.
This is thanks to a two clutch system responsible for their odd and even gears. In addition, DCT transmissions, like engine control units (ECUs), can be tuned to improve their performance by giving the driver faster and smoother gear changes. Since it takes an average driver 0.2 seconds to upshift, saving every second counts in performance scenarios.
Differences between DSG, DCT and PDK
Car manufacturers often gloat about how their latest vehicle offers DCT, DSG or PDK. To the unskilled eye, this may seem like extra marketing, although it’s far from the case. These are all variants of dual clutch transmissions that are usually manufacturer specific and suitable for their performance vehicles.
DCT is an acronym for dual clutch transmission and is commonly found on BMWs. DSG is an acronym for a direct-shift gearbox that is often combined with VAG vehicles, such as Volkswagen and Audi. Finally, PDK stands for Porsche Doppel Kupplungs, which translates to Porsche dual clutch transmission. These sequential gearboxes all come in the form of wet and dry clutch configurations that help them shift as fast as they do.
The Pros and Cons of DCTs
Like most car features, there are pros and cons to each added part. Here are some of the quirks and drawbacks of a dual clutch transmission.
One of the best things to come out of these automated manual transmissions is the insanely fast gear changes. Thanks to the dual-clutch design, the next gear is always on deck, resulting in faster and faster shifts than with a manual transmission. With the impeccability of the shifts, missing a gear is never in the equation. This is crucial in performance scenarios where you need to have every ounce of horsepower on the ground at all times.
Since dual clutch transmissions are performance oriented, many people often overlook the high mileage that comes with buying such gearboxes. As these gearboxes are highly efficient, this results in excellent performance on and off the track.
The disadvantages of sequential transmissions are few, although some exist. Because these transmissions have so much to offer, they clearly require more service than traditional automatic transmissions. ATF service is absolutely necessary for these gearboxes as they are very sensitive and rely on hydraulics to work properly although using apps the maintenance is not that bad.
Clutch packs can wear out like traditional manual transmissions, though their repair process is much more complex than its counterpart. As a result, these types of transmissions drive differently than those with torque converters. Rolling backwards on hills and shifting into neutral are all things to consider when purchasing a vehicle equipped with such transmissions.
DCT: fast and efficient switching
Automated manual transmissions can do more than just shift quickly. Because these gearboxes are highly efficient, they give you more miles per liter on the highway, while saving milliseconds on gear changes. While you lose the driving experience, the performance of dual clutch transmissions tries to compensate, although that is ultimately up to the driver to decide.