The 1500 Classic is a half-ton full-size truck. As a regular cab model it can seat up to three passengers. Extended cab models can carry up to six passengers. It is powered by hybrid technology, however it is not propelled by its electric motor. Instead, its electric motor takes over other tasks in order to save gas and manage engine power. None the less, GMC still considers it a hybrid vehicle.The GMC Sierra 1500 Hybrid Classic is a carryover from 2006.