As much as I love leds and what can be accomplished with them, they are an absolute horrible idea for retrofitting into a reflector housing that was not designed for them. There’s a good reason they’re illegal in many places, whether or not it gets enforced (around here it does not, unless they’re blue/purple/etc), whether or not someone is actually caught or fined. The glare on almost all of them is really atrocious and they do NOT light up better or further than the halogens the fixtures were designed for. There are illusions to the eye, yes, and some of that comes from glare (that affects other drivers, but not you), and some of that comes from the change in color temp. I bought some of the newer gen a few years ago (no light pipe but a much better approach to orientation and die size than most of them) and it was a big mistake. My lenses were nice and clear, not all all yellowed or crazed (that’s very important), adjusted correctly and checked carefully to book specs, and I still got flashed by several drivers in the two nights I had them installed. Downroad visibility was the same or slightly worse, could see a little more to both sides and right in front of the bumper, but overall it was not an improvement and honestly the 6000K-ish got a little tiresome on my eyes when driving in rural areas. I did notice that reflective street and traffic signs were a lot brighter and would light up from farther away…which told me right away there was a ton of glare to others even if my eyes couldn’t make it out as well just looking at the beams. Took those out pretty fast. Got a new car after that with projectors and tried the same bulb design…no improvement although the housing of course did better in terms of glare. Went back to the halogens.
Factory LEDs seem to be either really good or just decent, depends on whose they are. The cold white temp is awful, though, and I seem to hear more and more that people do not like them as much, especially in rain and fog. I think LEDs will arrive sometime soon and hopefully they will adopt a warmer temp in the 4000K-4500K range.
But if you have reflector housings, please just skip the LED bulbs for them. Looks cool, might look better in urban areas if you don’t care about other drivers’ vision, but just clean up the lenses (or replace the housings if they’re really bad) and put some new halogens in. That is a huge improvement for many cars and people don’t realize how “dirty” their old lenses and bulbs were until they see crystal clear again.
Lots of previous threads here on BLF (and on CPF, but older) and almost everyone seems to agree that they’re not a good choice, and why. If you have to find out for yourself, just do the best you can for a proper installation (like a real proper installation) and take your chances. I know upgrade kits, if available for your car, and super expensive and very involved to install, but that’s really the way to go if you just can’t live with your halogen.
My polite two cents and experience.