George,
The electronic speed limiter should be to not allow the vehicle to exceed a certain MPH. They are offering these options to parents to limit the speed their children can drive. The RPM limiter is built in to either the fuel or ignition system so when the vehicles engine reaches a pre-programmed value, it either takes fuel away or cuts the ignition to keep the engine RPM from over speeding. In the days before all of our electronics you could over speed your engine and stress or destroy it.
The statement below is off a site where they talk about Ford problems with technicians. They talk about both items you referred to. The governor is the speed limiter, and the rev limiter is the RPM one.
Hope this helps, Bob
It is a rev limiter built in to the computer. You can't remove it without a chip.
Don't ask me why, but it's there. I hate it and I also hate the governor that kicks in at 90.
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