H4 LED Car Headlamp question


Has anyone tried one of these led lights for their cars?

I believe most people would say they are bad for reflector headlamps as it caused too much spill for oncoming cars.

But since they are xml2 I was planning on dedoming them or swapping the cool white to a 4c tint or warmer

Linkys don’t seem to work.

I think if you can get the focus ok, then there should be no issue. I know some will proclaim it is not possible, but I honestly don’t believe that. My Maglites where designed for incan bulbs, yet you can focus an LED in them perfectly. And not all H4 bulbs are mead equally anyhow, they come in a fair degree of different shapes, widths and lengths.

Without seeing these bulbs, my only concern would be durability and how they shed the heat. As well as their actual output. If they aren’t significantly improving on regular H4 halogen bulbs, then I see little point in going to the effort and cost of LED bulbs. Most that I’ve seen, even the complete LED units have been underwhelming in terms of performance and mind boggling in price.

I friend of mine installed these in his car, but instead of XML it was MKR. Surprisingly, it worked well, puts out some useful light similar to the stock headlamp but with less reach. The tint was better, but I wouldn’t say it is any significant improvement over the stock xenon bulb. I’m safe to assume that a pair of decent HID would perform much better.

I can’t enter your link but the one I’m talking about has a little fan in the back and aluminium heatsink. It still got hot to hold but with the car on movement I think it should be fine.

i tried these, not sure if you talking about similar ones, your link is broken

and they turned out to be total garbage.

i tried them in 2013 accord, with projector headlights. illumination wise, they were worst than stock halogens. there was also noticeable amount of vibration felt when i put my hand on the headlight, also 1 ballast\driver started to flicker next day.

These LED bulbs are crap with projector lens because they use a parabolic reflector designed to work with halogen/xenon/HID bulbs with 360° light, the LED only covers <180° and if the connector is manufactured with a wrong angle it will only shine to a side or upwards.

But for reflector lamps it is acceptable, depending on the car you install it to. Personally I wouldn’t depend on aftermarket LED bulbs for low beams.

the bulbs that i tried had leds on both sides, they looked like cxa series, 115* so in theory there was 230* coverage, the beam looked more or less even, but weak. and pattern on the wall was not what halogens would make. seemed a lot like it was out of focus, mine had only low beam, no solenoid, high beams were separate bulb with reflectors.

i still do want to try different bulbs in my 2016 sonata, for high beams only. i too think things would be different in reflector light. thou i’m leaning more towards rapid start hid, now that they are available

Car headlights most commonly use complex surface reflectors which are very carefully designed to give uniform brightness without hot spots, dark spots or excessive glare. They are designed to work with a light source with specific brightness and geometry, i.e. size, shape, orientation and position. If you can replicate the original light source perfectly with LEDs they will work perfectly acceptably, I’ve yet to see an LED bulb that can do this.

A Cree XM-L2, well driven can deliver about 1000 lumens at the emitter, an H4 bulb will give roughly 1500 lumens. The LED needs significant heat-sinking which a plastic headlight just can’t provide so they can’t run them at the power levels they need to perform acceptably in terms of brightness. I’ve bought a good number of LED automotive bulbs, the only ones I found which were suitably bright to replace an incandescent didn’t last, they cooked themselves in a matter of weeks.

sounds about right

LED in cars is completely doable but it has to be engineered from the ground up to reflect the LED light output characteristics properly

If you want more light out of H4 headlights, you can use Philips X-treme Vision +130%.
These are much brighter than the “factory H4 bulbs” (Osram Bilux 64193) of my Dacia MCV II (more light, whiter light (3700K)).

And the Philips X-treme bulbs are approved for road use, led conversions are not approved because the light beam will not be correct (blinding other road users).

Fit a Hid kit as others have said.
These led direct replacement bulbs are ok for indicators etc or possibly even fog lights, but are useless for headlights
Fitting a hid kit bulb to a headlight designed for a halogen bulb normally works well and gives a much better more usable light output, especially on older cars, obviously care needs to be taken to make sure the headlights are set up correctly to avoid dazzling oncoming drivers.

Led headlights need to be designed from the ground up and can’t be replicated by putting an led bulb in place of the original halogen bulb.

I’ve converted many of my cars to hid if they weren’t all ready, works great and a vast improvement over halogen.

But if you really want led headlights, but a car with them, I speced my car with led headlights, they are amazing and that was three years ago so they are probably even better now.
Or wait a bit as apparently we will soon be seeing laser headlights apearing on cars very soon :slight_smile:

Then blinding oncoming drivers will no longer be considered a figurative statement

LOL! :smiley:


I hope this link works.

HID’s are always recommended by almost everyone but will they work on H4 bulbs? I mean H4 had Hi and Lo beam on the same bulb and most of the HID kids I see don’t offer that. Plus HID’s are always in cool white or neutral white but never warm white like the halogens.

Currently I am using Osram Nightbreaker Plus and they are indeed bright. Just not too sure how 2 xml2 would compare over ordinary halogens

It’s here already, BMW and Audi euro models only. US DOT does not allow them.

I can spot aftermarket HID kits by the combination of blue tint and the glare. If you start looking in detail at beam pattern and beam uniformity you’ll find that although they’re producing more lumens at the arc, that doesn’t translate into better vision for the driver, plus everybody else gets dazzled by the glare.

That is what I have done. Using Philips X-treme Vision +130% is a simple swap & gives much better light & is road legal.