I have a problem with all the senseless hype promoting inferior LED bulbs/assemblies. Headlights are after all safety devices and that's an area that should rely on truth and not hype. The worst offense of course is installing H4 LED bulbs in reflector headlights, a favorite of pick-me-up owners in this area. But there are others. For example, lumens is often used as a measurement and is completely bogus for judging the comparative performance of various LED's. The key metric to use is candela. Let's just go directly to Daniel Stern:
Objectively measured numbers that _do_ correspond to something the driver will see/be able to use are peak intensity in candela and its location within the beam (these figures describe seeing distance provided by the headlamp), and intensity at 15 degrees left and right for low beam, and 12 degrees left and right for high beam (these figures describe the beam width).
Here are measurements Daniel provided me at my request regarding the Philips Integral Beam LED assemblies that we use in our Gold+ and Platinum Series:
The Philips LED H6024 has:
• a low beam peak intensity of 54,300 candela, which is between 4x and 5x the low beam peak intensity of a similar-size H4 headlamp. The minimum requirement in this region in US regs is 15,000 candela, and the minimum requirement in this region in European regs is
• a low beam peak intensity located at 1.4° down, 1.6° right, which is about 1° closer to straight-ahead than a good similar-size H4 headlamp (the closer the peak intensity is to straight-ahead, the longer the seeing distance)
• a low beam intensity at 15°L of 10,190 candela, and at 15°R it's 10,200 candela. The minimum requirement in US regs is 850 candela—this Philips lamp provides a _very_ wide beam!—and there is no requirement in this vicinity in European regs.
• a high beam intensity of 78,600 candela, located 0.5° up and 0.2° right. The US reg limits intensity straight ahead to 75,000 candela, and this lamp, straight ahead, provides 72,100 candela. This is a very strong high beam, right up against the max allowable output.
• a high beam intensity at 12°L of 20,400 candela, and at 12°R it's 9,600. The requirement is at least 1,000 candela in both of these locations, so here again—very wide beam.
Hopefully that will help you to make informed decisions when buying LED lamps. Ask 'em about candela's and angles.
Best,
John