- 06/17/2025
- 6 Min Read
- By: Christian Schaefer
Is The DCT In Trouble? The Traditional Automatic Has Finally Caught Up To The Dual-Clutch Transmission
2004 was quite a year for the world. Americans had an election, the summer Olympics were held in Athens, and Volkswagen/Audi debuted the most significant new automotive product in decades: the dual-clutch transmission. At the time, it was a major leap forward, as it delivered the best of the automatic and manual transmission, and was thought to make the former obsolete. But that revolution occurred two decades ago, and much has changed since.
The DCT has largely remained the same, with some updates along the way, yet the traditional automatic transmission has seen a revolution that few expected. Its current status is arguably the best it’s ever been, thanks to manufacturers like ZF and Aisin. An impossible thought two decades ago, but many of us now ask ourselves: has the automatic transmission surpassed the dual-clutch?
The Automatic And The Dual-Cutch: Two Pedals, Two Ways
We often take for granted that we simply push a button to start our car’s engine after opening a door that unlocked itself because it detected the key in our pocket. A century ago, drivers were changing ignition timing and fuel mixture from the cockpit while also operating pedals that weren’t guaranteed to be in their current and standard orientation. Complex operation like that drove automakers to improve accessibility to more drivers by simplifying their vehicles. That took form in many ways, like the electric engine starter to the Magneto, but it wasn’t until 1939 that drivers could find themselves in a vehicle that shifted through the gears by itself.
The Hydra-matic was a revolutionary transmission, offering drivers an ease and simplicity that was mostly unheard of in the era. General Motors’ engineers had already made motoring easier by introducing the world to the synchromesh manual transmission about a decade earlier, but clearly not enough. Years of engineering brought designers through a few variations on the concept before landing on the same basic principles that automatic transmissions continue to use: a fluid coupling in place of a friction clutch connected the engine to the hydraulically controlled planetary gearsets within the transmission.
Seeing use in the following conflict in all sorts of vehicles, including light tanks, it was a fully proven concept by the time passenger car production restarted in the late forties. A decade later, the idea was under production in Europe, with Mercedes debuting the first of a long line of automatic transmissions in 1961. It offered the operational simplicity automakers needed to market their vehicles to the broadest possible audience, and it's stuck around ever since as the choice for people who don’t want to shift themselves. However, it never matched the precision of manual transmission in performance applications.
Despite its effectiveness in passenger cars and large equipment, the automatic was slower, less reliable, less precise, and less durable when beaten hard. Great for luxury, where going places in comfort was the goal, the “slushbox” was not a high-performance device for anything outside American drag racing. The synchromesh manual was the best option for anything meant to move quickly, and it was so for decades. Meanwhile, automatic transmissions continued to evolve into quicker-shifting, durable options that, while still slower and less effective than a manual, were eventually offered as competent options in performance models.
Throughout that time, though, a small group of engineers had other ideas. The same year GM debuted the Hydramatic, French military engineer Adolphe Kégresse devised the dual-clutch transmission as we know it today. Unfortunately, a lack of funds prevented the creation of a functional prototype. It would take another forty years, but Kégresse’s design would ultimately see the light of day as a functional and practical gearbox thanks to Audi and Porsche.
Two of the most dominant figures in motorsport in the eighties were Porsche’s 956/962 prototype endurance racer and Audi’s Sport Quattro rally car. Both models featured a manual transmission at inception but received dual-clutch transmissions around 1985/86. They were effective but ahead of their time, failing to translate to the road cars of the era. It wouldn’t be until the mid-’00s that VAG and Porsche would see the dual-clutch fruits of their long-established labor.
Appearing first in the VR6-powered Audi TT, the DSG and PDK—VW/Audi and Porsche’s names for the technology, respectively—began a modern revolution that saw nearly every major automaker adopt the new gearbox. It offered the smooth and simple driving experience of an automatic, with the ability to give the driver direct control with a push of the gear selector. It could also hold more power than a traditional automatic while being far quicker and more precise. It was even more fuel efficient, thanks to the lack of a fluid coupling (torque converter). In many ways, it married the best aspects of the manual and automatic into one easy-to-use gearbox.
Oddly enough, VW and Porsche have had separate suppliers for their respective DCTs since the beginning. Borg Warner and Volkswagen first brought the DSG to market in 2004, before ZF and Porsche followed in 2009 with the PDK. BMW also had a DCT option provided by Getrag in that same era. Considering how much better it was for performance and fuel efficiency, it wasn’t difficult to feel like the dual-clutch was in the market to stay for good. But ZF wasn’t committed to giving up on the traditional auto, even if their DCT was regularly considered the best on the market, and soon after delivered what many consider the modern benchmark for two-pedal driving.
ZF’s Revolution: The 8HP Eight-Speed Automatic
Improvements to the automatic transmission’s performance capabilities were slow but steady over its first sixty years. Mercedes was arguably the closest to a reliable and sporty automatic gearbox with the 722.6 five-speed, which had found a home in all sorts of machines, from every AMG product of the day, to Chrysler’s big V8-powered machines, to the 996.2 Porsche 911 and its variants. The SpeedShift variants meant for AMG models featured a manual gear selection mode and more aggressive gear selection when it was automatic, with later models receiving steering-wheel-mounted shift paddles. Mercedes’ follow-up—the seven-speed 722.9—was quicker, more reliable, and more efficient than its predecessor, but it still couldn’t match the DSG and PDK for speed and engagement.
ZF, the supplier for Porsche’s PDK, had the 6HP, a similarly widely used automatic in that same early ‘00s era. As many Audi and BMW owners can tell you, the 6HP is a fine transmission that can be modified to shift relatively quickly, but it’s not without its faults. Valvebody seals and shift solenoids are known to wear out, directly causing shifting issues or causing excessive wear elsewhere in the gearbox, which can lead to shifting problems. While developing the PDK, ZF engineers also happened to be designing the 6HP’s replacement, focusing on improving efficiency rather than engagement and shift speed.
Fossil fuel emission concerns were in full effect at this point, forcing everyone to push towards ultimate efficiency, and ZF’s then-new 8HP eight-speed automatic was the embodiment of that. Advancements over the 6HP covered every area of the transmission from the torque converter to its shift elements. Lighter components and simplified mechnicals reduced drag from the rotating components within the gearbox. That also meant it was lighter than its predecessor without growing in size. More than that, it was designed to be modular, making it easy for ZF to adapt it to many engine and drivetrain orientations. It was even future-proofed with the capability of adapting to all sorts of hybridization via replacement of the torque converter. On its own, the 8HP equated to a 6% improvement in efficiency over the 6HP, and if equipped with the requisite Stop/Start technology, pushed that figure to 11%.
However, most enthusiasts and journalists will agree that its performance characteristics were the most positive outcome of the efficiency push. Removing parasitic drag within the transmission would reduce the fuel required to spin it, and ZF pulled out all of the stops to get there. Key to that was completely redesigned gearsets and their associated shift elements. Moving to eight forward gears also tightened the ratio spread, so the engine had less RPM to drop to reach the next gear, aiding shift speed. While it couldn’t pre-select the next gear like a dual-clutch, it was still good enough for shifts as quick as 200 milliseconds; plenty close enough to its rival.
Advancements with the torque converter’s lock-up clutches and the introduction of the Twin-Torsional Damper provided a significantly quicker lock-up, aiding efficiency and feel. The latter matters most to enthusiasts, as historically, the torque converter has given the automatic its slushy reputation. Torque capability is also critical to those looking to boost engine performance beyond factory levels, and the 8HP has shown to be more than capable. Aftermarket tunes are popular and add some robustness to the automatic, but it should be able to handle simple bolt-ons without much fiddling. Anyone looking to make serious power won’t have to look elsewhere, either, as more than a few companies offer stronger internal components to build an 8HP into a motorsport-capable gearbox.
Altogether, ZF delivered a product that has seemingly not left the height of praise since the motoring world took notice nearly two decades ago. The efficiency has been a huge selling point for many automakers, as seen by its broad adoption in the face of ever-tightening restrictions, but those aren’t the benefits most have continually praised it for. have always been a recipe for going faster, and combined with a couple of ZF’s key advancements, it’s made the 8HP a quick-shifting, direct, and robust transmission.
Catching Up To The DCT - Is There A Clear Winner?
The 8HP’s success didn’t come overnight, but after a handful of years and a few evolutions, it remains one of the most popularly available transmissions. More so now than ever, it’s the choice for performance vehicles like Audi’s S and RS models and all of BMW’s M cars. Not long ago, many were certain the DCT wouldn’t ever be topped, but it seems to have fallen out as the go-to for two-pedal driving. So why is that?
Realistically, there are a few deciding factors. In the case of the Audi B9 S5 and S4, and the larger models like the C8 S6 and D4 S8, VAG simply didn’t have a DSG capable of withstanding the torque their engines were producing. While other manufacturers may not have had the same issue, the ZF 8HP is well-known for its proven torque-withstanding capabilities among enthusiasts. However, the less powerful Audi B9 A4 and A5 models received a new seven-speed DSG, and the soon-to-be B10 S5 will again have a DSG, showing Audi hasn’t given up on it yet. Considering BMW’s engines are just as, if not more capable, than Audi’s various turbo V6s, it’s easy to assume they used them for similar reasons. That said, cost is also a significant factor.
Using a handful of transmissions in a single platform means more engineering, testing, designing, and parts stocking than finding a single option that works for all. One option means minimal extra engineering for models with more performance, and creating an external oil cooler and more aggressive shift map for the transmission is much cheaper than prepping a chassis for a completely different one. As mentioned above, the ZF 8HP responds well to aggressive tuning; brands like BMW have made that work for them. On top of that, the 8HP is less expensive to produce and maintain than a dual-clutch, making it a better option for manufacturers when building vehicles and for servicing costs under warranty.
Speaking of under warranty, the cost of repairs is another significant difference. Dual clutches are very reliable until they aren’t. Internal faults with Distance Sensors and mechatronics units are common among the Porsche and VAG transmissions. Solenoid issues are less common but have caused issues for some. In many cases, the dealership’s fix is a complete transmission replacement. Few problems will be met with anything further than diagnosis. Minor issues like unsmooth take-offs and jerkiness at low RPM are mostly ignored or met with a fluid replacement and computer reset. Luckily, the aftermarket has come in to fill the gaps where replacement parts are needed, though the replacement processes are much more difficult than the average DIY. On the other hand, the 8HP is a dime a dozen, and while different from predecessors, it’s still fairly traditional, so most modern transmission repair shops should be able to service and repair the ZF box.
Automakers also have trends to consider, and the automotive market has shifted considerably since the DSG’s debut in ‘04. More buyers are interested in the special, high-performance models and what they offer, but fewer are interested in the motorsports connection and feel. In most cases, the ZF 8HP delivers 90% of the driving engagement of the DCT but with better manners around town, where less-enthusiast-driven owners would find fault with the occasional low-speed jerkiness of the dual-clutch. Higher-end performance models like Porsche’s GT models, AMG’s GT models, and almost every other supercar and hypercar retain the DCT, where buyers are paying for the best performance automakers can provide.
The bottom line is that ZF’s 8HP has bridged the gap between performance characteristics and everyday ease of use. It’s less complex to build, easier and less expensive to repair, less expensive to make, just as adaptable to hybrid drivetrains, and performs nearly as well under motorsport-like stresses. Not everyone has given up on the dual clutch, but many have fallen for all that ZF offers. Where we go from here is up to automakers and gearbox manufacturers, but you can bet that the traditional automatic isn’t going anywhere anytime soon.
