Autoblog

Volkswagen's dual-clutch gearbox (DSG) has proven that a balance can be struck between driver involvement and running the daily slog without a cramped left leg, with a bump in fuel economy to boot. As reported earlier this year, VW has plans to introduce another cog onto its six-speed DSG unit, while at the same time dropping the wet clutch arrangement for a dry-clutch setup. Now it's official: the new seven-speed DSG not only boasts another gear and dry clutches, but it's the first time the DSG transmission is able to be mounted for a front-traverse setup.

The seven-speed 'box will originally be available on the Golf and Golf Plus models abroad, equipped with the 1.4-liter TSI engine and 1.9-liter TDI mill, and the 1,750 euro premium over the base model also includes a hill-start assist system. The next generation, Borg-Warner-developed DSG has the capacity to channel 184 lb.-ft. of torque to the wheels, which should suit both models well, but it will need some beefing up before it becomes standard on more performance-oriented models.

Porsche originally pioneered a working version of the dual clutch gearbox concept on some 962 Group C cars in the late 1980s, but it took until 2003 for the design to show up in production vehicles. When Volkswagen introduced the six speed DSG in various Audi, VW, and Skoda models, it used dual wet clutches in a setup designed and built by Borg-Warner.

The DSG has half the gears connected to one clutch with the other half connected to the second clutch. It works essentially as two interwoven gearboxes tied to a single output. As one clutch is engaged, the other is disengaged and shifted. When it's time to go up or down a gear the corresponding gears on the open clutch are coupled and the two clutches swap positions. At that point the gears on the opposite are coupled in preparation for the next shift.

This year, Volkswagen is introducing a new-generation DSG with an extra gear and dry clutches. The new seven-speed gearbox is more compact than the original and more efficient thanks in part to the dry clutches. Because of its smaller size, the new box can be used in models all the way down to the Polo. VW will start building the new gearboxes late this year and they will appear in the Golf with the 1.4L TSI gas engine and the 1.9L TDI diesel. The 1.4L TSI is also new, and like VW's other TSI engines uses direct fuel injection but uses only a turbocharger rather than the twin turbo/supercharger setup used on the other TSI mills.

[Source: VW]