"Hi-yo Silver" was the command often given by the Lone Ranger to his horse Silver to urge him to break into a fast gallop, in the Western radio and television series The Lone Ranger.

At the Pohatchee Drive-In in 1955, Marty whispered the same command to the DeLorean, imitating the Lone Ranger, as he prepared to accelerate fast enough to travel to the Old West. As Marty drove past him, Doc shouted another Western film quote, "Happy trails, Marty!"