I'm sure it's one of those things that varies by state. Here in MN, mileage is required on the title for all vehicles less than 10 years old. When selling a vehicle, you have to declare the current mileage and sign off on it. You also have to mark a box that indicates whether it's the actual mileage, the mileage in excess of the odometer's limits, or not the actual mileage. If the vehicle is more than 10 years old, you don't have to declare the mileage.