Beginning in the late 90s and the early 2000s, GM began to phase in a new variant on the 4L60E, the 4L65E. This transmission introduced a new set of 5-pinion planetary gears as well as a newly improved and stronger output shaft. This gave the transmission the ability to sustain the extra torque of the newer engines that were being installed around that time. Monster provides a variety of performance ratings in their vehicles, including mild, heavy duty, super sport, and SS Xtreme.