Being a former rep for a manufacturer who has had speedometers on their electric equipment for some 15 years, it has it's pros and cons. In a warehouse invironment, if one operator has a lift that "registers" a mph more than someone else, the other operators complain. On the older IC equipment the only way to limit the travel speed is to limit the engine RPM via the air governor, This does limit the power of the unit to climb grades and limits the lift speed. It CAN even cause an overheating problem in some operations.

The best way to control the maximum speed is a system that has a VSS, vehicle speed sensor. It would have a "pickup" on the differential ring gear, transmission or torque converter. One of the units mentioned in previous posts may do this. GOOD LUCK!