The knowledge requirements are lower, too, due to less complexity, so training and study times are reduced in comparison.
In addition to the flight training hours, private certificate students can expect to spend some 200 hours in ground instruction and private study in order to pass the FAA knowledge exam. The sport-pilot certificate requires a total of only 20 hours of flight time. Light-sport aircraft use less fuel than traditional training aircraft due to their smaller engines, so they're cheaper to operate and rent. The knowledge requirements are lower, too, due to less complexity, so training and study times are reduced in comparison. According to the FAA, national training times average 30 hours for the sport-pilot certificate.