Test Sheet: Project #101: Efficacy of H4 LED Bulbs in Reflector Headlights

AC Beta Test Team Checklist


Philips Ultinon Pro6000 H4 LED Bulbs

1)    Try them out in as many conditions as possible, use low beam and high beam, and closely observe how the headlights work—the light will certainly seem brighter and whiter on the road surface close to the car, that's a given, so try to look beyond that.

2)    How's the distance reach?

3)    The spread? High and low beams?

4)    In rain or fog, do you get objectionable back-scatter?

5)    With the lamps switched on and the car in a garage, is there more upward stray light (on side and front walls and ceiling, above the beam pattern)?

6)    With an LED bulb on one side of the car and a halogen bulb on the other side, shine the headlights at a wall about 20 feet away after dark.

  1. Is the low beam cutoff and upsweep preserved with the LED bulb?
  2. Are there holes/shadows or streaks/spots in or around the beam pattern?


7)    Enlist a helper with another car, and try to check for glare on a 2-lane road—oncoming, as well as with the LED-bulb-equipped car behind you so you can check for excessive mirror glare. 

8) How would you compare the LED bulbs to the bulbs that you have been using?

9) Do they generate a worrisome amount of heat?