After two years on the market, BorgWarner Inc.'s innovative dual-clutch transmission (DCT) technology is on the verge of becoming a formidable force in the gearbox sector, as the supplier says it expects to produce several million units annually within three years.

The new technology, known internally as DualTronic, enables a manual transmission to perform like an automatic, without the annoying “torque-interrupt” that accompanies conventional manual shifting or single-clutch automated manual transmissions.

Volkswagen AG has been BorgWarner's development partner for DCT, which appears on VW, Audi, Skoda and SEAT-brand vehicles. VW refers to the transmission as DSG (direct-shift gearbox).

The auto maker assembles the transmissions and integrates BorgWarner's “mechatronic” control unit and wet-clutch assembly.

By 2008, several other customers beyond VW also will use the dual-clutch technology, and not all of the contracts are BorgWarner's.

German transmission producer Getrag GmbH & Cie KG says it has several development programs for the innovative transmission, some with and some without BorgWarner as a Tier 2 component supplier.

Getrag's first job will start production in 2007, followed by three additional customers launching in the 2008-2009 timeframe, says Friedemann Strasser, president and CEO of Getrag's U.S. operations.

For some of these contracts, BorgWarner will supply the mechatronic control unit and clutch assembly to Getrag, which will integrate the components into the transmission module before shipping to the OEM customer. For other contracts, Getrag will purchase the clutch and control units from other sources.

Frank Guenter, director of program management-DualTronic for BorgWarner Transmission Systems, says auto makers and transmission producers in Europe, the U.S. and Asia/Pacific are showing tremendous interest in DCT.

“Currently, there are no OEMs that are not looking into DCT and not in contact with BorgWarner,” Guenter tells Ward's. He confirms BorgWarner will have more customers, beyond the VW family, for DCT by 2008.

Currently, BorgWarner is producing about 250,000 DCT units per year. With the arrival of new applications, Guenter says total DCT output could reach several million units annually within three years.

The supplier produces the mechatronic modules in Tulle, France, and the clutch assemblies in Arnstadt, Germany.

BorgWarner expects DCT to be installed on 18% of new passenger cars in Europe by 010 and to gain a foothold in North America and Japan during that time.

DCT uses twin clutches that are automatically engaged — there is no clutch pedal. The technology allows automatic shifting of gears that is extremely fast — even sporty — yet significantly smoother and more precise than single-clutch automated-manual transmissions also available on the market. The driver also can shift manually and sequentially, if desired.

The transmission earned universal kudos in reviews of the first vehicles in Europe to feature DSG, the VW Golf R32 and Audi TT, equipped with the 3.2L V-6. The TT was the first vehicle to reach the U.S. with DSG, in summer 2003. The R32, however, was never available with the DSG transmission in the U.S.

The New Beetle 1.9L TDI is available with a 6-speed automatic transmission with DSG. The new transmission also will be available across the lineup for the new Jetta when it arrives. First up is the Jetta TDI, which goes on sale in the U.S. in April, followed by the DSG-equipped 2L turbo gasoline I-4 model in August.

In Europe, the Touran compact van is available with DSG, and installation rates have reached 20% — considerably higher than anticipated, Guenter says.

In May, when the Audi A3 4-door hatchback goes on sale in the U.S., the DSG will be optional with the 2L turbo gasoline I-4 and standard with the 3.2L V-6 (with quattro all-wheel drive).

BorgWarner's relationship with VW is not exclusive. The module the supplier sells to VW is proprietary, but Guenter says the overriding technology can be packaged in unique ways for other customers. “We're looking at other applications,” he says. “We can adjust the technology to the individual customer.”

Identifying the next customer for DCT is speculative, but Ford Motor Co. appears to be a solid bet. BorgWarner supplied a clutch module derived from DCT for Ford's recent Freestyle SRV hybrid concept car.

And since 2001, Getrag has operated all of Ford's manual-transmission plants in Europe. One of DCT's attractive attributes is its ability to be manufactured with minimal modifications to traditional manual-gearbox plants.

DCT is based on a manual-transmission architecture, and its higher torque capacity is well suited for increasingly powerful turbodiesel engines. Besides the racecar-like shifting, DCT also saves fuel, largely because it does not use the efficiency-sapping torque converter found in conventional automatic transmissions.

After two years of testing in the marketplace, Guenter says many drivers achieve fuel-economy gains of up to 15%, when compared with conventional 4- or 5-speed automatics.

However, when compared with more advanced 6- and 7-speed automatics, the fuel-economy improvement is more modest, in the range of 5%, he says.