On 29/03/2021 01:07, Dave Plowman (News) wrote:
In article ,
Steve Walker wrote:
There is a blanket ban on aftermarket HID and LED, to a car originally
fitted with tungsten. Regardless. Yet many new vehicles cause dazzle.

That is not quite correct. They can only be fitted with E-marked
replacements, so if an E-marked headlamp assembly is available, it can
be retrofitted.

HID lamp units have motorised self levelling, so would generally need more
than just plugging in. Unlike after market HID conversions or the simpler
LED.

However, not all cars type approved and factory fitted with HID or LED
headlamps have self-levelling or wash systems - the MOT rules have had
to take this into account and a vehicle can fail for such systems not
working, but cannot fail for them not being present. If such lights were
an option for your vehicle, you can retrofit them.

The regulations should state beam pattern and intensity. Both are easy
enough to check at MOT time.

Beam pattern is the big one. With the correct beam pattern, intensity is
far less important.

My car has projector (bullseye) dips. These give a perfect beam pattern
with tungsten, HID or LED. To do with the flag which cuts off the top
being exactly in the focal plane, which gives a very sharp cut-off. Plain
reflector types give a lot more scatter regardless of bulb type.

Which is why retrofitting LED lamps into existing housings does not meet
type approval. Wheareas fitting complete E-marked lamp assemblies can.