After having our 22 etron GT for 2 months, testing with the lane centering, I found that there are 2 modes, 1 is standard without ACC and 1 within the ACC. The standard one the steering is heavier and only pulls the car back in lane when it drifted outside the lane. The one that turned on in the driver assistant CC is lighter and keeps the lane constantly centered and works spot on. This is just my observation, all cars and road may be different. My tires pressures are 39PSI on all 4 and new.
