2014 CLA CLASS COUPE ・ Photo by Mercedes-Benz
Once regarded as the best solution for automatic gear-shifting in performance cars, the dual-clutch transmission (DCT) has begun to slip from favor. While a few major manufacturers continue to be major proponents of the technology, others either failed to adopt it or have moved on to more highly developed conventional torque-converter-based automatics and continuously variable transmissions of various types. The major advantage of the dual-clutch transmission is its ability to execute extremely rapid gear changes. Each DCT is essentially was two separate transmissions, one providing the odd-numbered speeds (first gear, third gear, fifth gear) and the other providing even-numbered speeds. The twin transmissions are joined with two clutches, and they work in tandem. As each gear is engaged to drive the vehicle, the next higher numerical gear is pre-selected so that it can be engaged virtually instantaneously when the transmission’s automatic logic or the driver’s manual selection chooses it. Shifts typically are completed much faster than with a manual gearbox. At the same time, some DCTs shifts can feel abrupt and harsh in everyday driving, prompting many car manufacturers to use different technology.
The recently redesigned Mercedes-AMG CLA 45, the performance sub-brand's four-door compact sports coupe, is one of the latest cars to feature a dual-clutch automatic transmission. As you would guess from its Mercedes-AMG designation, the CLA 45 is performance-oriented in the extreme. It is powered by a 382-horsepower 2.0-liter engine that Mercedes calls the world's most powerful turbocharged four-cylinder manufactured for series production, accompanied by the AMG Speedshift DCT-8G dual-clutch transmission with eight gears. The transmission's gear ratios have been configured so that the driver experiences very "spontaneous acceleration" in all speed ranges, combined with fast-shifting, optimum connections when shifting up through the gears and automatic double de-clutching when shifting down. Thanks to AMG Dynamic Select driving mode, a feature of the DCT, each driver receives a specific drive configuration with different accelerator and gearshift characteristics based on how they drive. For ease in everyday driving, a "gliding" function can be selected in the "Individual" driving mode.
Photo by Mercedes-AMG
The new-generation Porsche 911 sports car (with the code name 992) was introduced to the United States with a dual-clutch transmission the only choice, demonstrating Porsche's continuing belief in the technology. At the same time, the recent announcement that the 992-gen 911 could be ordered with a manual transmission was very warmly greeted by the Porsche community. The 911's DCT is an eight-speed PDK, and its super-quick gear changes are instrumental in the 911's stellar three-second zero-to-60 mph time. Over the course of several decades, Porsche has been a prime mover in the development and use of dual-clutch transmissions. PDK is the brand's acronym for "Porsche doppelkupplungsgetriebe," which means "Porsche dual-clutch gearbox." The sports car and SUV maker started using the technology in its racecars in the early 1980s and continues to include it in the current 911 flagship.
Photo by Porsche
The Audi S3 is a performance-enhanced version of the brand's popular A3 luxury compact sedan. It is equipped with a 288-horsepower turbocharged 2.0-liter TSFI four-cylinder engine that brings with it 280 lb-ft of torque, a significant boost from the A3. To emphasize the S3's sportiness, this sedan comes with Audi's seven-speed S tronic dual-clutch automatic transmission, also used on the higher-performance Audi RS3 and various other specialty Audi vehicles. Fast, positive shifts are the transmission's hallmark, although attention has also been paid to limiting "shift-shock" and harshness in everyday driving. The S3 features Audi's famous Quattro all-wheel drive system, which uses sensors and computer logic to maximize traction as it works in concert with the DCT. The S3 also is equipped with a wide variety of connectivity and driver assistance features.
Photo by Audi
The 2019 Volkswagen Golf R is the most powerful version of the brand's popular four-door hatchback. (VW suspended production of the Golf R for the 2020 model year, but it’s expected to return in the near future; 2019 inventory remains plentiful as of this writing.) The R features one of the most powerful four-cylinder production engines in the world: the same turbocharged, direct-injection TSI 2.0-liter engine as the Audi S3, producing 288 horsepower and 280 lb-ft of torque. To optimize its performance, VW offers the model with a seven-speed DSG dual-clutch transmission very similar to the Audi’s. Golf R models with the DSG automatic also feature a stop-start system designed to help save fuel when the engine would otherwise be idling needlessly. All Golf R models are equipped with Volkswagen’s 4Motion all-wheel drive. When operating under a relatively low load or when coasting, only the front wheels are driven and the rear wheels are decoupled, helping to save fuel. When the system senses the need, however, the rear wheels are engaged in fractions of a second via the center differential, activated by an electro-hydraulic oil pump.
Photo by Volkswagen
The Nissan GT-R sports car needs no introduction. Over the course of 50 years, it has become one of the industry's performance icons. This iteration of the GT-R is powered by a 565-horsepower 3.8-liter 24-valve twin-turbocharged V6 engine, each one handcrafted by its own takumi technician. For the 2020 model year, the GT-R is upgraded with new turbochargers, which help increase the engine's low-rpm response due to an abradable seal that provides tighter clearances and a 5 percent increase in efficiency. The 2020 GT-R Premium version of the car has a six-speed dual-clutch transmission with an "R mode" designed for both road and track use. In that mode, the DCT downshifts more aggressively for quicker cornering exits. Gear selection takes place during the engagement of the antilock brake system, resulting in reduced understeer. The DCT also features adaptive shift control that changes the shift schedules to fit the user's driving style.
Photo by Nissan
Audi says its mid-engine R8 sports car is the pinnacle of performance for Audi, with no other model bearing a closer tie to racing. Enthusiasts around the world agree and applaud the model's ever-increasing performance. For 2020, the naturally aspirated 5.2-liter FSI V-10 engine in R8 V10 Coupe produces 562 horsepower, and that prodigious horsepower is delivered by a seven-speed S tronic dual-clutch transmission, which can shift gears in as little as 120 milliseconds. Able to draw on 30 more horsepower than the previous year's model, the powertrain allows the slippery coupe to jet from zero to 60 mph in 3.4 seconds. Audi says the car's top track speed is 201 mph. Updates to the 2020 R8 include an updated front bumper with a new honeycomb grille with R8 badge, front spoiler lip, and lateral air intakes. The updated rear bumper has honeycomb air outlets, oval exhaust pipes, and a new rear diffuser. The headlights have also been darkened, and the rocker panel has been redesigned.
Photo by Audi
The Volkswagen Jetta GLI is a higher performance version of the brand's popular compact sedan. Sometimes referred to as a "VW GTI with a trunk," its mission is simple: to deliver a German performance sedan at an affordable price. The Jetta GLI is powered by a 2.0-liter turbocharged direct-injection TSI four-cylinder engine that delivers 228 horsepower and 258 pound-feet of torque. The engine, which is shared with the Golf GTI, features variable valve timing on the intake and exhaust sides, as well as variable exhaust valve lift. The front-wheel drive Jetta GLI comes standard with a six-speed manual transmission, while a seven-speed DSG dual-clutch transmission is on the options list. DSG-equipped models come with a start/stop system designed to help improve fuel efficiency. This technology switches off the engine during what otherwise would be engine idle when the brake pedal is held, and when the brake pedal is released, the engine restarts. With the DSG, the Jetta GLI is one of the most affordable DCT-equipped cars on available in American showrooms today.
Photo by Volkswagen
Like the Volkswagen Jetta GLI, the 2020 Hyundai Veloster Turbo sports coupe brings the quick-shifting efficiency of a dual-clutch transmission into the affordable range. The Veloster Turbo and Turbo Ultimate are two high-performance versions of the attractive hatchback. The Veloster's standard engine is a 147-horsepower 2.0-liter Atkinson-cycle four-cylinder engine, but the Veloster Turbo offers a 1.6-liter turbocharged direct-injection four-cylinder engine that delivers 201 horsepower and 190 lb-ft of torque. In the Veloster Turbo, the engine is backed by a standard seven-speed EcoShift dual-clutch transmission with paddle shifters. That transmission is optional in the Turbo Ultimate version of the car. For those who need more complication in their lives, Hyundai also offers a Veloster N performance version with a higher horsepower 2.0-liter turbocharged engine, but it lacks the dual-clutch transmission.
Photo by Hyundai
One of the most delightful cars featuring the availability of a dual-clutch transmission is the Alfa Romeo 4C. Bearing the name of a brand legendary for its racing successes, the mid-engine 4C Coupe and 4C Spider deliver seductive Italian styling to accompany their racing-inspired carbon fiber monocoque chassis. The car's over-achieving all-aluminum-alloy 1.7-liter dual-intercooled turbocharged engine produces 237 horsepower and 258 lb-ft of torque. As you would guess from its inclusion here, the engine is fitted with a 6-speed Alfa TCT (twin-clutch) transmission, enabling drivers to immediately imagine being a Formula 1 piloto. That ability is enhanced by the inclusion of Alfa DNA Pro Drive Mode Selector with four adjustable drive modes. Interestingly the Akrapovic dual-mode exhaust system is linked directly to the drive modes, enabling drivers to choose their own exhaust "soundtrack." Weighing less than 2,500 pounds, the Alfa Romeo 4C can streak from zero to 60 mph in a little over four seconds.
Photo by Alfa Romeo
The Hyundai IONIQ Hybrid and Ioniq Plug-In Hybrid four-door hatchback are among the most unusual cars to feature dual-clutch transmissions. Designed for ultra-high fuel efficiency, the Ioniq hybrids have an exceptionally low drag coefficient (0.24 Cd) and both are powered by a 1.6-liter direct-injected Atkinson-cycle four-cylinder engine tuned for thermal efficiency. The engine offers a modest 104 horsepower and an estimated 109 lb-ft of torque, yet it is combined with a quick-shifting six-speed double-clutch transmission. The use of the DCT is a major part of Hyundai's efforts to distinguish the Ioniq from the segment-leading Toyota Prius. The Ioniq's gasoline engine is supplemented in the hybrid version by a 43-horsepower (32 kW) electric motor, and Hyundai estimates total system horsepower to be 139. The Plug-In Hybrid is fitted with a 60-horsepower (45 kW) electric motor, and its lithium-ion polymer battery gives it an all-electric range of about 27 miles.
Photo by Hyundai