Having driven down a moderate hill, there is no difference in regeneration from cruise control set spped, paddles set for similar speed or just using the brakes, only difference is if the wheels bounce when using brakes it will switch to discs, which does not happen with paddles/ SCC. Due to the wheel bouncing, paddles / SCC is better for twisting steep hills but not relevant to long motorway descents. Best option is to watch the power screen or power bar, this will jump to 0 when the car switches to discs, it then has no regeneration, in my experience.Although.....looking at page 5-19 of the owner’s manual of my newly-acquired 2017 Ioniq, it warns: “When descending down a long or steep hill, use the paddle shifter (left side lever) to increase regenerative braking control in order to control your speed without using the brake pedal excessively. Applying the brakes continuously will cause the brakes to overheat and could result in a temporary loss of braking performance.”
So doesn’t this imply that the brake system is partially or fully independent of the regen system?