The HyBall gives suggestions on accelerator pedal usage.
Try to keep the ball inside the white circle, since this is the position that usually gives the best results in fuel efficiency.
If the HyBall is over the white circle, release accelerator pedal and the ball will go down.
If the HyBall is below the white circle, you can press the accelerator pedal a little more.
A good adapter and a fast phone are essential for good results: an OBDLink adapter is mandatory for 4th generation HSD cars.
It's strongly advised to use a HUD or HUD-like placement for the phone, so you can keep your eyes on the road at all time.
Suggestions provided by Hybrid Assistant, during the usage of the HyBall feature, can not account for road conditions: the driver is the only responsible for evaluating and applying them only if they do not pose any danger to driver, passengers and surrounding cars and people.