Ford To Offer Mileage-Maxing Six-Speed Dual-Clutch Transmission
Ford has confirmed that the first North American application of its new line of dual-clutch PowerShift transmissions will be on its small car lines starting in 2010. While providing no specific fitment roster, a variation on this automated gearbox is already used on the European Focus. The new Fiesta, which also arrives here in 2010, also is likely to have a PowerShift in its future. Ford says this automated dual-clutch technology can increase a vehicle's fuel economy by up to nine percent versus a conventional four-speed automatic.
Offering the convenience of an automatic but with the precision of a manual transmission, PowerShift is capable of performing up/down changes while maintaining uninterrupted torque delivery. Functionally, the gearbox is the equivalent of two manual transmissions working in parallel, with one clutch activating the odd-numbered gears and the other, the even-numbered cogs. A computer electronically coordinates interactions between these two in a way that ensures a seamless flow of power.
Unlike its counterpart in the Euro Focus that uses twin wet clutches to handle the relatively higher levels of torque produced by that car's turbodiesel engine, the U.S. PowerShift package has a dry-plate setup like any conventional manual transmission. According to Piero Aversa, manager Ford Automatic Transmission Engineering, it provides a better match for the anticipated duty cycle. "A dry clutch is a real sweet spot for lighter vehicle applications, because it eliminates the need for various pumps, cooling components and hydraulic fluids." As a result this new six-speed PowerShift transmission is nearly 30 pounds lighter than the conventional four-speed automatic currently used in the Focus. Aversa also notes that beyond being lighter, more durable, and more efficient, the PowerShift transmission is a sealed-for-life design that requires no regular maintenance.
Other tricks in the PowerShift playbook include mileage-boosting neutral coast-down circuitry that disengages the clutches when the brakes are applied, Hill Mode that prevents rollbacks on uphill starts, a low-speed creep mode that simulates the action of a conventional automatic and a calculated degree of clutch slip that acts as a supplemental vibration damper to smooth powertrain operation and help reduce noise levels.
Ford has already started introducing new, more efficient six-speed transmissions of all types into its North American fleet and expects to have a virtual 100 percent fitment rate by 2013.