Automatic transmissions are designed to simplify the driving experience by managing gear shifts electronically or hydraulically, allowing the driver to focus on the road without manual gear changes. They typically come with a set number of gears but do not add extra gears in the same way that auxiliary transmissions, multi-speed rear axles, or sequential transmissions can.
Auxiliary transmissions provide additional gears, effectively multiplying the number of gear ratios available to enhance performance, especially in heavy-duty applications. Multi-speed rear axles also serve to increase the gear range, allowing for a better adaptation to different driving conditions. Sequential transmissions can facilitate quicker shifts by allowing drivers to change gears in a precise sequence, often without needing a clutch, but they also do not simply adapt existing gears; they modify how gear changes occur.
Hence, while options like auxiliary transmissions, multi-speed rear axles, and sequential transmissions do add extra gearing to enhance performance and efficiency, automatic transmissions maintain a set range without this modification.