As time goes on, customers will find car or truck headlights is darker. At that moment, I think you need to consider replace headlights.

As usual, automotive headlight bulbs need to be changed after 2 years because lumens of headlights cut down so much.

When you put headlights for kc hilites gravity, please note halogen bulbs or led bulbs.

Halogen headlight bulbs easy to be installed and also cheap, but led headlights can be used longer time.