Rapper Xzibit and California governor Arnold Schwarzenegger will appear together on a very special Earth Day episode of MTV's "Pimp My Ride" on April 22.

XXL reports today that the unlikely duo will watch as the crew of Galpin Auto Sports turns a beatdown 1965 Chevrolet Impala into an 800-horsepower monster that runs on biodiesel, a cleaner-burning diesel fuel synthesized from vegetable oil.

"I am very encouraged by the great potential in converting vehicles to run on biodiesel as a way to reduce greenhouse gas emissions," said the governor.

The episode will air at 1 p.m. EST and will be immediately followed by a very special episode of "The Hills," in which Lauren is "like, totally torn" between clubbing with Heidi or staying in on a Friday night to watch An Inconvenient Truth with guest star Al Gore.