Low Beam Bulb Replacement on the NC Miata

I've been wanting to upgrade the headlight bulbs on my Miata ever since I got it almost 5 years ago and I figured I should probably do it now before I need to drive home in the dark this winter.

I didn't want to be forced to do it when a light burns out because I wanted the luxury of doing it when I had light and warm weather.

I picked up a $12 set of LED H7 Bulbs on eBay (free shipping) hoping that LED bulb technology has advanced far enough for them to be useful. I was specifically looking for lights where the chip is very nearly at the same distance as the original halogen bulb so the optics in the headlamp assembly's reflector won't act too weird. This is termed "1:1 design form factor".

Passenger side:

-remove the windshield washer fluid tank with a 10mm socket. There is 1 bolt and a nut.

-press the tiny button on the plug for the bulb and pull it straight back. I was pulling for 10 minutes before I discovered the dumb button and needed to review the comments on a youtube video before I knew to look for it.

-pull the rubber grommet straight back to expose the mounted bulb.

-the actual bulb is mounted to an adapter. Take a look at the orientation before you swap bulbs.

-reinstall in reverse order of removal ;)

-pay special attention to match the notch on the adapter to the headlight mounting surface

-don't wait too long to do the driver side because you will need the muscle memory to work the driver side bulb off, working blind

Driver side:

-jackup front of car

-remove wheel

-unfasten fender liner and fold it back enough to work your hand in there to work. I use a bungee cord to hold it back out of the way. This is really not as bad as it sounds. There's barely any room around the fuse box, though you could try to unbolt it.

-you might be able to peer down the side of the fuse box while you work your hand under the fender liner to get a view of what your hand is doing. I had to use my phone to take a picture to figure out how and where the spring retainer goes.

black adapter is not aligned properly in the base's slot

Alas, the beam pattern is not as bright as the 20k lumens it is advertised to be (10k lumens per side should be plenty bright). The driver side beam seems to not be aimed properly and I'm wondering if something is not seated properly (improper alignment made the beam pattern incorrect on the driver side).

I'm going to need to take another look.

Some listings note that these style bulbs are not suitable for projector beams, but they have reflectors just like regular headlights, so I'm not sure if this should be a concern.

* One week later *

I picked up the LED bulb on the right that is also 1:1 sized but includes active cooling in the form of a tiny fan at the base of the bulb which should improve on the likelihood of hitting the claimed 10k Lumens per bulb. I think Walmart beats Amazon by a buck or two on this particular product.

product link:

https://www.walmart.com/ip/AUXITO-H7-Led-Headlight-Bulb-50W-10000LM-6500K-Cool-White-Cooling-Fan-No-Adapter-Required-Easy-Install-Conversion-Kit-Fog-Lights-Halogen-Replacement-/1901663953

$12 vs $37

The instructions for these bulbs suggest ensuring that the LED chips face the 3 and 9 o'Clock positions when installed, but the bulbs can't be adjusted and there's no way to adjust bulb position on the Miata either. Standard orientation results in the chips facing 12 and 6 positions which should be fine also.

Now that I have experience changing these bulbs a 2nd time, I was able to swap them in about 20 mins.

The $37 lights from Walmart are significantly brighter. The active cooling definitely allows the manufacturer to run brighter, more powerful LEDs but despite the brighter lights they still don't quite throw enough light down the road to illuminate very far, so I'll leave the high beams as halogens. This could pose a reaction time issue when traveling faster than the speed limit on the highway because you might not see far ahead enough to avoid an obstacle in the road.

I suspect the temperature color (more yellow) lends to the visibility/contrast.

I'm hoping that the tiny cooling fans have room/clearance to do their work reliably. There were no complaints from oncoming drivers during my test run.

Caution: Beam patterns in these night pictures seem much brighter than in real life. The camera exposure can't reproduce the dimness that I perceive from the driver seat.