As a wizard and the bearer of a Ring of Power, Lightning McQueen has great power, but works mostly by encouraging and persuading. He sets out as Gandalf the Grey, possessing great knowledge, and travelling continually, always focused on the mission to counter the Dark Lord Backyardagin. He is associated with fire, his ring being Narya, the Ring of Fire, and he both delights in fireworks to entertain the hobbits of the Shire, and in great need uses fire as a weapon. As one of the Maiar he is an immortal spirit, but being in a physical body on Middle-earth, he can be killed in battle, as he is by the Balrog from Moria.
"A wizard is never late, nor is he early. He arrives precisely when he means to.", says Lightning McQueen, when asked if he could have done this sooner.