An F-150 is a half-ton Ford pickup, and that's what they've called it for a while.
- F-150 - a half-ton
- F-250 - a 3/4 ton
- F-350 - a one-ton
- F-450 - a 1.5 ton
- F-550 - a 2.5 ton(?) - I can't remember if that old grain truck we had when I was a kid was an F-450 or an F-550.