Toyota PRIUS Owner's Manual page 366

366
4-5. Using the driving support systems
Accelerate or decelerate the
2
vehicle to the desired speed
(above approximately 40 km/h
[25 mph]) and push the lever
down to set the speed.
Cruise control "SET" indicator will
come on.
The vehicle speed at the moment
the lever is released becomes the
set speed.
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