27 Articles

Why do automatic transmissions now get better fuel efficiency than manuals?

Not so long ago, it was common for automatic transmissions to be referred to as slushboxes, since that's how they often behaved. Rather than use a mechanical clutch, traditional automatic transmissions use a fluid coupling between the engine and the gear-sets to transmit drive torque. This provides some benefits, but isn't a perfect system.

General Motors has reached an agreement with one of its primary Chinese partners, Shanghai Automotive Industries Corp. (SAIC), on the joint development of powertrains for small vehicles.

General Motors has reached an agreement with one of its primary Chinese partners, Shanghai Automotive Industries Corp. (SAIC), on the joint development of powertrains for small vehicles.

Fuso Duonic dual-clutch-transmission – Click above to enlarge

Ford PowerShift transmissions on the line – Click above for high-res image gallery

Ford PowerShift transmissions on the line – Click above for high-res image gallery

Ford Explorer America Concept - Click above for a high-res image gallery

2010 Mercury Milan Hybrid - Click above for high-res image gallery

2010 Audi A5 Sportback - Click above for high-res image gallery

Audi has just added a new transmission option to European-market versions of the A4 and A5. The company's 7-speed S-Tronic dual clutch gearbox is now available with the 2.0L TFSI four cylinder. The A5 picks up 0.3 seconds in the 0-60 run and cuts 1g/km of CO2 emissions with the new gearbox. In the sedan, the mileage is unchanged at 31.8 mpg compared to the 6-speed manual. Here in the U.S., the A4 2.0L currently comes standard with a CVT while manual and conventional automatics are optional.

Over in the UK, drivers buying a new Passat CC now have a new transmission option that gives them an extra 1.2 mpg. The 160 hp 1.8L TSI four cylinder can now be paired with VW's 7-speed DSG dual clutch gearbox in place of the 6-speed manual. The DSG yields a combined 32.2 mpg (U.S.) compared to the 31.0 mpg (U.S.) with the manual. Similarly, the CO2 emissions have dropped from 178 g/km to 172 g/km. The 2.0L TDI diesel and gasoline 3.6L V6 are available with the 6-speed DSG, in addition to the ma

Now that Chrysler's deal to build dual clutch transmissions in a joint venture with Getrag is officially kaput, the company will stick with its existing 6-speed automatic for now. In early 2007, Chrysler announced the deal with Getrag to supply up to 700,000 transmissions a year that could cut fuel consumption by six percent. It was part of a series of powertrain announcements that included the new Phoenix V6 engine family. Getrag was unable to raise the $300 million needed to pay for its toolin

Click above for a high-res gallery of the Audi S3 Sportback

The current credit crisis could be playing further havoc with Chrysler's future powertrain product plans. In the first half of 2007, Chrysler announced investment plans to build two new engine plants and a transmission plant for 2010 model cars. The transmission facility was to be a joint venture with Getrag to build fuel saving dual clutch transmissions. Chrysler already offers German-built Getrag DCTs in the European specification Journey and Sebring. Unfortunately Getrag's apparent inability