My UK Gen 4 Prius has a speed limiter. It is activated using a steering wheel button and the speed is then set by a push down on the cruise control stub lever. I have noticed that when it is active the blue guidance bar on the HSI is not shown. It works well, stopping the car from exceeding the set speed under normal conditions however it feels like it does this by countering the accelerator with the brakes or at least regen. If so, holding the car to the set limit is not going to be good for fuel consumption. Does anyone know how it works?