Originally Posted by
Cobrajet
Most folks think that a sixth gear is simply a higher freeway gear added on top of a five-speed for the purpose of improving economy. But this usually isn't the case. All of the other ratios are changed as well, and each gear becomes 'closer' to the next (called a close-ratio transmission).
Six-speeds are usually offered to increase performance, not economy. Thus, the sixth gear in a six-speed would likely be nearly the same ratio as the fifth gear in a five-speed.
In an economy car like this I certainly would not expect a six-speed to ever be offered.