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.
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
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
While Porsche has made it abundantly clear that they have no concerns about trying to meet new corporate average fuel economy standards in the U.S. in the coming decade, that doesn't mean that aren't doing anything to improve the fuel consumption of their cars. Relative to their performance, Porsche cars have always comparatively efficient anyway, with the current 2008 Carrera 2 coupe be being rated at 18mpg city/26mpg hwy. That's a lot better than most SUVs. That's actually better than a V6 Sat
We knew already that the 2009 Dodge Journey would be receiving a dual-clutch transmission for overseas markets, but Chrysler has just announced that the '09 Dodge Avenger and 2009 Chrysler Sebring will also offer the tranny. Mated to a 2.0 liter diesel engine, both fuel economy and CO2 emissions will improve by about six-percent. Chrysler's dual-clutch transmission is jointly produced by Getrag. One clutch engages the even ratios while the other operates on the odd. Efficiency is increased due t