The auto-levelling feature is a mechanism that automatically corrects the vertical deviation of light axis resulting from changes in suspension due to weight and also under hard acceleration. This helps to relieve dazzle to oncoming vehicles.

For example, if the vehicle is carrying more passengers or luggage and the rear is lower, the headlights would adjust downwards to reduce glare to oncoming traffic without compromising the improved visibility HID headlamps give to drivers. On the other hand, if the vehicle is carrying a lighter load and the rear is raised, the headlights would adjust upwards to illuminate the roads properly.

Source:LTA