* Regular Cab: Has two doors and a small, often non-existent, rear seat. It's designed primarily for two people, offering maximum cargo bed length. Think of it as a work truck focused on utility.
* SuperCab: Has four doors, but the rear doors are smaller "suicide" doors that open toward the rear. It offers more rear passenger space than the Regular Cab, albeit limited compared to the SuperCrew. It provides a compromise between passenger capacity and cargo bed length.
In short: Choose a Regular Cab for maximum cargo space and minimal passenger capacity. Choose a SuperCab for a bit more passenger room, but with a shorter cargo bed than a SuperCrew.
