What is what kind of truck is optimus prime?

Optimus Prime is a fictional character from the Transformers universe. He is the leader of the Autobots, a group of sentient robotic beings, who are involved in an ongoing battle against the evil Decepticons. In his vehicle mode, Optimus Prime transforms into a powerful and iconic tractor-trailer truck. The design of Optimus Prime's truck mode has evolved over the years, with various iterations appearing in different Transformers media and toy lines. Overall, Optimus Prime is often portrayed as a strong, noble, and wise leader who uses his truck mode to ferry his Autobot comrades into battle.