Autoblog

For 2009, the Ford Escape and Mercury Mariner (as well as the Mazda Tribute) are getting the powertrain updates that they missed out on when their exteriors were revamped last year. While the 2008 models had all-new looks and interiors, the engines and transmissions were carried over from 2007, including the four-speed automatic transmissions. We'll have more info on their new 2.5L four-cylinder and 3.0L V6 engines after we drive them next week, but Ford released some information on their new six-speed transmissions when we visited its Van Dyke Transmission Plant in Sterling Heights, MI.

The new 6F35 is a completely new six-speed automatic that will have a wider total ratio spread than the four speed it is replacing. The top gear ratio will be approximately the same as the four-speed, but the lower gears will be shorter helping off-the-line acceleration. The final drive ratio will be a little taller (numerically lower), which will help reduce the engine speed when cruising on the highway. Even with the larger first to sixth spread, the overall gap between each ratio will be smaller resulting in less engine speed drop during shifts and a quieter, smoother overall driving experience. The 6F35 uses a total of three planetary gear sets and five clutches to generate the six forward and one reverse gear.

Ford is claiming that the new transmission contributes to a 4-6% improvement in fuel efficiency depending on with which vehicle and engine it's paired. Besides the three CUVs launching shortly, the new gearboxes are also going into the revamped Ford Fusion and Mercury Milan early next year. The Van Dyke plant also builds the larger 6F50 used in the Edge, Taurus and their derivatives, as well as a smaller four-speed used in the Focus. That four-speed will also be replaced by a third smaller 6-speed in the next year or two for the Focus and Fiesta. Ford plans to double production of six-speed autoboxes by the end of 2009 to 1.4 million units and by 2012 expects 98% of all its automatics to be 6-ratio variants.

[Source: Ford]