Quote Originally Posted by crosstrekmy18 View Post
I'm looking to upgrade the fog lights on my 2018 Limited. My knowledge about lighting and cars in general is limited but I've been reading a lot the past few days. Though initially motivated purely by aesthetics, I would like the LED upgrade to perform better than the halogens. I do mostly city driving and make at least one trip to the mountains (dirt back roads, low light sparsely populated roads) every month. And of course I need to get through the snow ice and rain in the northeast.

So, what is better?
- Should I be looking for more distance? Since the Limited has LED headlights, do I need distance?
- Should I look for more breadth? Light the corners of the road better?
- Can (or should) I get best of both?

Here's what I have pieced together about LED upgrades in general. Please correct me if I'm wrong about any of this.
- plainly swapping out the LED isn't optimal since the housing is built for halogen. Performance may be poorer than halogen with lesser throw (?). Do this only for aesthetics and just brightness (?).
- upgrade with housing for best performance

Thanks for reading.

P.S. If this post will derail the thread, I can certainly start a new thread. I just thought my post might fit here since the thread seems to be LED 101 and might help others who stumble across this thread.
Happy to answer that!

You want to maintain the same output pattern as your OEM fog lights, while producing more overall output. Distance isn't as big a concern since it's not a primary driving beam, but having some width will make them more helpful in foggy conditions.

You are correct in that most LED replacements do not utilize the OEM halogen reflector optics correctly, that is, until we released our SL-series line of LED replacements. They do an exceptional job utilizing the factory optics, produce more output, with no added glare. Here's an output comparison we just did with a WRX this week:



Notice how the SLF has the same foreground pattern as the OEM halogen bulb? That's due to the fact that our engineering team placed the LED chipset as close to the position of the halogen filament as possible. It was done using a sophisticated optical modeling software program.

Two other advantages:

1. Cool white ( SLF is 5,700K ) will match OEM LED DRLs & HIDs nicely for a huge cosmetic upgrade
2. Yellow fog lights, if you want that look, ours are a great looking yellow! (Designed by our lead electrical engineer who has a 2015 STI)

Thank you for asking!
Nick C.