DSG: dry or wet clutch? The differences and how to identify the version in your car

• Dry-clutch DSGs work without an oil bath. Wet clutches run in oil, which carries heat away from them, so they can handle more torque and longer periods of slip.
• Volkswagen quoted up to 250 Nm of torque for the seven-speed DSG with dry clutches and up to 350 Nm for the six-speed DSG with wet clutches. That's why more powerful engines have wet clutches.
• The number of gears doesn't reveal the version. In 2017, the Škoda Octavia III had seven-speed DSGs with both dry and wet clutches.
• The reliable way to identify the version is the gearbox code in the car's build data. A main dealer can look it up from the VIN.
• A wet DSG needs regular oil changes. A dry DSG suffers more from long periods of creeping in queues and from hill starts, especially when towing a trailer.

DSG is the Volkswagen Group's dual-clutch gearbox, found in Škoda, Volkswagen, SEAT and Cupra models, and at Audi under the name S tronic. How it works and what to expect from it is explained in the article on the DSG gearbox. This article answers one specific question: does a DSG have a dry or a wet clutch? Both versions transmit the engine's power through friction between the clutch surfaces. The difference is whether the clutches run in oil. That determines how powerful an engine the gearbox can cope with, how it handles queues and towing, and what maintenance it needs. Yet in an ad, both versions appear under the same abbreviation and often with the same number of gears. Fluid servicing by gearbox type is covered in the article automatic transmission fluid change.

A clutch heats up mainly when it slips, that is, when pulling away, creeping slowly and manoeuvring. These are the moments when the speeds of the engine and the gearbox are being matched. A fully engaged clutch hardly heats up at all. With wet clutches, the oil carries the heat away. Dry clutches have to cool down on their own, which is why they cope less well with prolonged slip.

Volkswagen provides the specific figures. When it introduced the seven-speed DSG with dry clutches in 2008, it was for engines with up to 250 Nm of torque. The six-speed DSG with wet clutches of the time was designed for up to 350 Nm. This gives a rule of thumb: if the engine's spec sheet shows significantly more than 250 Nm, expect wet clutches. With engines up to 250 Nm, either version is possible.

The DSG badge, the number of gears or a description such as ‘2.0 TDI automatic’ in an ad won't tell you the version. The same model may have received a different gearbox during its production run, and the all-wheel-drive version often uses a different solution too. The reliable route has three steps:

1. The exact version of the car: generation, engine, power output, year of manufacture and whether it's front- or all-wheel drive.
2. The gearbox code: you'll find it in the car's build data or service documentation. A main dealer can look it up from the VIN. The VIN alone won't tell you the clutch type.
3. Matching the design to the code: the technical data for the gearbox code will tell you unambiguously whether it has dry or wet clutches.

Dual-clutch gearboxes from other brands, such as DCT or EDC, are also made with both dry and wet clutches. The way to identify them is the same.

Example: three different DSGs in the Škoda Octavia III

The Škoda Octavia III (2012–2020) shows clearly why the abbreviation in an ad isn't enough. In the 2017 line-up, it was offered with these versions:

The first and third rows disprove the shortcut ‘seven gears = dry clutches’. The second and third rows show that the same 2.0 TDI 110 kW engine could have a six-speed or a seven-speed DSG, depending on the drive layout. In both cases the clutches were wet.

In normal flowing traffic, you won't notice any difference. Both versions shift quickly and without interrupting drive. The difference shows up wherever the clutch slips for a long time.

What about maintenance?

On a wet DSG, regular maintenance includes an oil change, usually with a new filter. The interval is specified by the manufacturer for each gearbox; there's no single interval for all DSGs. With a used car with a wet DSG, it's therefore worth looking for a record of the oil change in the service history.

A dry DSG also has oil in its gear train; the clutches just don't run in it. The clutch pack wears much like the clutch of a manual gearbox. Its lifespan depends heavily on how much the car has been crawling in queues and around town.

You don't choose the version separately; it comes with the engine and drive layout. If you're looking for a small or compact car with a smaller engine for everyday use, there's no need to fear dry clutches, and you'll benefit from lower losses in the gearbox. If you tow a trailer regularly, drive in the mountains or spend a lot of time in queues in a hilly city, you'd do better to choose a more powerful engine with wet clutches.

• ‘A seven-speed DSG has dry clutches.’ There are seven-speed versions with wet clutches too.
• ‘A dry DSG has no oil at all.’ Only the clutches are dry; the gearbox's gear train needs oil.
• ‘The same engine means the same gearbox.’ The drive layout and the year of manufacture can change the combination.
• ‘A wet DSG can take anything.’ Better heat dissipation doesn't eliminate wear, and a skipped oil change harms the gearbox.

The condition of a particular gearbox is revealed by the service history, diagnostics and a test drive, not by the clutch type.

When you're looking for a specific combination of engine, drive layout and gearbox, a large selection helps. Carvago offers roughly a million used cars from sellers across Europe. So even for a less common version, such as a more powerful diesel with a wet DSG and all-wheel drive, you're choosing from a selection that's usually an order of magnitude larger than on the local market.

The condition of the gearbox doesn't remain unknown. Every car is checked by a technician before sale as part of the CarAudit™ inspection with up to 270 checkpoints. The inspection also includes diagnostics and a test drive, and you know the result before you decide to buy. Carvago stands behind the condition stated in the CarAudit™ certificate.

Carvago gives every car a free extended warranty. It doesn't include problematic models in its offer at all; that's what the Carvago Blacklist is for.

Can I tell a dry DSG from a wet one on a test drive?

Not reliably. The smoothness of pulling away and shifting is influenced more by the gearbox's calibration and wear than by the clutch type. On a drive, you'll learn more about the gearbox's condition than about its design.

Can I tell the version from the gear selector or the paddles behind the steering wheel?

No. The shape of the selector, the paddles and the sport mode tell you nothing about the clutch type. Both versions usually have these controls.

Does the split into dry and wet clutches also apply to S tronic at Audi?

Yes. S tronic is Audi's name for the Volkswagen Group's dual-clutch gearboxes, and it exists in both versions. As with DSG, you identify it through the gearbox code.

Can dry clutches be swapped for wet ones?

No. The wet version is a different gearbox with its own oil system, cooling and control. It's not simply a matter of replacing the clutch pack.

1. https://uploads.vw-mms.de/system/production/files/vwn/003/768/file/e451eac3067123ff305d27a85f3e7eb73dd1ee6f/DSG_the_intelligent_automatic_gearbox_from_Volkswagen_2008_en.pdf?1530367024=
2. https://cdn.skoda-storyboard.com/2017/03/170307-Geneva-2017-Press-Kit.pdf
3. https://carvago.com/car-delivery
4. https://carvago.com/caraudit