The Ford Mustang is the Dr. Jekyll and Mr. Hyde of sport coupes, depending on the type of transmission matching the engine. Dr. Jekyll's persona comes in the mild form of an automatic that allows Sunday school teachers to commute along Pasadena streets without frightening the kids and grandmothers. Mr. Hyde's Mustang features a rock-crunching, close-ratio, manual transmission that leaves burning rubber at stoplights to impress the girls.
Background
Since its inception in 1964, the Mustang has always appealed to two types of drivers: those who want the sexy, sporty looks of the Mustang but good manners behind the wheel, and those who think hard driving and hard cornering is the only way to treat a Mustang. First-generation Mustangs were all about clean fun until Carroll Shelby created the Shelby Mustang GT350 and GT500 that demonstrated what a four-speed manual could do. Early Mustangs transmitted power from an in-line, six-cylinder or V-8 engine via a three- or four-speed manual or three-speed automatic. The bottom line is that manual transmissions allow for better handling, superior off-the-line acceleration and control, and usually better gas mileage. The automatic is simply a matter of convenience. No clutch, no hassles when commuting 10 mph on a jammed freeway, and a free hand to apply makeup or hold a cup of coffee.
Late Model Transmissions
Early fifth-generation Mustangs featured the Borg-Warner T-5 or Tremec TR-360 five-speed manuals, and then the Tremec 6060 manual. Automatic transmission choices included the 5R55S five-speed and 6R80 six-speed. Automotive journalists were more enamored with the manuals because their job was to hug curves at 50 mph, fly along streets a la Steve McQueen in "Bullitt" and generally thrash a factory test car. Many members of the buying public were more conservative. They ordered Mustangs with automatics.
Manuals
The venerable Borg-Warner T-5 was part of the Mustang lineup for many decades, although outgunned by the later six-speed manuals. The T-5 has a reputation for versatility as a match for in-line four- and six-cylinders, as well as V-6 and V-8 engines. The Tremec 3650 was more sophisticated than the T-5, with its fifth gear functioning as overdrive. The Tremec in the standard 2005 Mustangs matched the V-6 and V-8 and the Mustang's 3.31-to-1 rear end. The Tremec 6060 six-speed also featured an aluminum case. Ford used the 6060 in Shelby performance cars, although without an optional short-throw kit, the driver may have difficulty downshifting into fourth or second because of the long throw. However, the six-speeds are equipped to handle abuse from hard drivers.
Automatics
After 2005, the Mustang received the SR55S five-speed or SR80 six-speed automatics. The SR55S was generally reserved for the V-6-powered Mustang and the SR80 for the V-8s. There's a bit of a role reversal between the manual and automatic in the post-2005 Mustangs, as the six-speed automatics provided better gas mileage than the manuals. A six-speed automatic matched with a 305-horsepower V-6 could easily achieve 31 mpg in highway driving. (See References 4-6 and Resources 1-2)
0 comments:
Post a Comment