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Switching to LED lights for your car head lights - what you should know about it! Answered

With LED technology getting cheaper and better almost weekly now it seems to make sense to use them in your old car.
People who did it and post about it make the decisions even easier.
I mean who wouldn't want to switch from pale yellow candle light to these bright white litghts showing you all in great detail?

Problem is the firstly the legal side of things.
Many countries now allow the use of LED replacements for many older cars - within limits.
Where and if allowed it means you need to use LED systems that a compliant with your local road authorities and regulations.
In a lot of countries though it is still not legal to replace incandescent head lights with LED ones.
Why is this?

If you read this after changing over already you will have noticed a destinct difference between the two types of "globes".
The filament is very compact and in a H4 lamp the reflector is quite small and perfectly positioned as well.
In comparison to (mostly the non-legal) LED replacements the light emitting surface is flat and usually a lot bigger than the filament.
This means the light output and pattern changes as the reflector of your lamp is not designed to work with LED's and their bigger area of light surface.
Being flat also means the LED can not really produce the same amount of light in LUX to the sides as compared to directly above.
Most LED lamps compensate this with an added reflector in the front area.
So we have two major problems:
Not really enough light going sideways while too much light goes up and down in the LED system.
Too much stray light due to the bigger surface are that puts out the light.
Combined they result in light going into areas where it should not go, or not go at this level of brightness.
The often used statement that now even highway signs are easy to read at night on low beam clearly highlights this problem.
There is a good reason your head lamps should not shine upwards ;)

What can be done to allow for the use of LED lamps in old cars?
If not too old than your car already has H1/H7 lamps and indiviual for fog, low- and high- beam.
For those it is now quite easy to get road legal LED replacements.
Not so much though for the really old H4 systems with high- and low- beam in one lamp.
Don't be fooled by your local auto shop though!
Just because they might sell a lot of HID and LED lmaps does not mean what is on display for sale is actually road legal.
If it does not state the corresponding certifications for your country/state than you can rest assured a cop on a bad day will have field day (or night) with you sooner or later.
As said, in many countries there are now tested and legal option available.
Their main difference to the cheap and uncertified ones is not their higher price alone.
In comparison their more powerful LED's result in much smaller COBS -the LED strip giving the light.
Reducing glare and providing a much closer match to the incanscent lamps.

Why is it so hard to find a common ground and provide proper LED replacement systems?
You might as well ask why you can buy a $20 amplifier or a $5.000 amplifier....
When the first cars came out with LED lamps China saw the potential and provided all sorts of headlight lamps with LED's in them.
Quickly they not only made it to the international markets but also gained interest for basically everyone wanting more light.
Regulations were non existent back then...
Even today it is next to impossible to actually provide proper numbers in terms of lumen, LUX or general brightness.
What a LED provides can be quite different from what leaves the head lights.
Old standards only refer to Watt, so it is no problem to find a cheap LED system that provides what a 100W lamp would get you at less than 30W on the input side...
And the light color is not really specified at all in most countires.
France required a yellowish light back in the day.
A blue tint in your head lights was no problem with Xenon lights, so LED systems now go as high 7000 Kelvin, or close to a blueish light and as low as 3000 Kelvin or what is coming from incandescent lights.
You see, finding a common ground is already hard just with the light output and color alone.
There is only one real test that even today defines whether or not a head light needs adjustment or in case of LED replacements makes them illegal.
The good old white wall with the markers, lines and distance mark on the floor.

If you compare a properly adjusted head light on these test walls you get a very destinct pattern of light to see.
Clear cut off's, brightly illuminated areas within the fields and lines and less bright areas in the outer regions - again still defined by the marks on the wall.
Swapping to various types of LED replacements should provide the same patterns and brightness levels.
In reality though almost all of them will only give you a very bright and undefined big area on the wall.
No more dark areas with clear cut off to the bright middle section, even the formerly shadowish side areas are now well lit up.
Great for you behind the wheel, bad for everyone coming the other direction, especially when wet and raining.
Some people in the colder parts of the world will now what I mean when I say that some LED system will only give you good visibility when it snows if you turn them off ;)

How to check for yourself if your new LED lights are any good for other people on the road?
I assume you did the right thing and had your headlights checked and if required adjusted before actually putting LED lights in!
Nothing is worse than trying to get more light if said lights are adjusted to point everywhere except the road.
With your old light still in park in front on a straight wall on level ground, like your garage or any other wall you find.
Park at a nice distance to get a clean pattern on the wall that is not too big.
5 to 10 meters away should do fine.
Use some painters tape or similar to mark out your desgined light pattern on the wall.
Don't be too fancy, just some tape to indicate where bright light turn into way less on the wall and a few strips to indicate the cut off lines where patterns of brightness change on the wall.
Leave the car where it is and put your new LED lights in.
Check for yourself by how much the areas differ now.
Anything above your marked cut off lines means you are blinding other drivers ahead of you.
Anything way brighter than before on the sides could mean you also blind oncoming traffic on the other side of the road or freeway.
A pale and low light level in these areas is not too bad and can be acceptable.
Anything that clearly illuminates those formerly dark areas however should not be used on the roads.
Another check is to try at what distance your old low- and high- beam start to become a bit too birght too directly look in to when you stand in front of your car during a really dark night.
Look somwhere drak and move closer until you reach the discomfort zone.
With your LED lights you should be able to get as close as before ...


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