Firstly, i'll start by linking the Governments official stance on the legality's of HID's in the UK.

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The short of it basically says that unless the headlight units are "e-marked" (including the internals) then they are not legal on the UK roads.

It also states that they "must have headlamp cleaning and self-levelling."

Here is a vid of an Auto Express test showing the illegality of the simple retrofit kits without projectors.

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As far as practicality goes, assuming it's a projector unit and aligned correctly, there is unlikely to be any problems, even during MOT time.

As a result, it states that "In summary it is not permitted to convert an existing halogen headlamp unit for use with HID bulbs."

This renders all HID retro-fit kits (of which there are many on the market) completely illegal for use on the roads.

Some adverts state that the kits are not road legal, but a good 90% of the adverts i've seen on websites and ebay do not state anything like this. Most of them completely ignore any legal facts, even in their FAQ sections.


Practical alternatives are E marked headlight units, no self levelling or washing ont he Prelude but it shouldn't cause any issues currently.

5g Preludes have a fairly large selection of HID projector based headlight units, but the 4g does not.
From my searching, i can find one place in the states that do 3 different options for the 4g, black, chrome and another make version of the headlight with projectors in it. These are around $200 currently, i do not know if they will ship internationally or if they will adjust to RHD cars.


The other options for better lighting are brighter Halogen bulbs, options from Phillips (Extreme) Osram (Nightbreaker) and Ring (Xenon Max)

These are as good as you can get road legal, all around 90% brighter than a standard Halogen bulb. However, very few bulbs are standard halogen any more and the increase of 90% over what you already have is unlikely, though an increase non the less.

Most H4 type bulbs are rated as 60/55W which i understand to be the dipped beam and then the main beam output of the bulb.

It is stated that bulbs with an output of 80w and over are for off road use only.
It also is stated that they might not be suitable for all plastic lens headlights.

It does make me wonder why they don't boost the output of fancy bulbs to the limit for brighter light.


However, as you can imagine, HID's have been around since '98 (European standard since then, there is no UK standard since '88 and they're only accepted in the UK under the Euro standard)
Motorsport has required bright bulbs for a long time, mainly rallying.

Ring do a Rallysport bulb, well, several, as do some other companies, these bulbs are rated from around 100w output to 160w output.

Obviously these will be a lot brighter, but as stated, they're no longer road legal. However these are standard H4 (and other fitments) bulbs and as far as the old practicality goes, will be even more so than the HID's.


The problem when you go past the 100w mark, is that they draw more than the standard amount, i do not know what affect this will have on the wiring and electrical load of the car, but i don't think it will be good.

From what i've found, the 100w outputs draw the same, but i've yet to confirm these bulbs are exactly that and/or have all the same standards of a normal H4 bulb.

this is more like it.

ok 1st point..the TSX retrofit is the projector kit taken from the Acura TSX which i think is the american prestige equivalent to the honda legend / new accord..the bulb that is used in the retrofits is not a HID bulb..its called a D2s Bulb which is completely legal,

HID kits and the bulbs supplied with them are in fact illegal when used with reflector type lenses like the ones that come standard on preludes.

The D2s Bulb used with a projector lens is legal as the projector lens is desined to project light onto a target area i,e on the ground, as well as this it can also be adjusted manually to the desired height and in no way is blinding to oncoming drivers. the colour ouput is a bright white light rather than a blue / purple light but you do get a blue colour flicker much like most of the newer cars on the road today

the lighting output from the bulbs you mentioned such as the 100w and the 130 watt outputs are illegal and are for off road use only as they will literally blind oncoming drivers. as well as this they will only last for a few days due to the demand on the wiring and electrical components of our preludes. Now the reason i know this is because i used to use the 130w h4 bulbs in my car on the road (yes i know this was naughty) and they used to blow on me after about 2 days of continuos use. as well as the fact i used to get some really pissed off oncoming drivers showing me the finger on a regular basis.

I've not heard of those D2s bulbs, any more info on them?

I will also add that any Halogen bulb with bluing or other colouring will not be as bright as the white bulbs due to the coating they need to use to filter the light.


As far as the 130w bulbs, i understand they draw more than normal, but the 100w ones draw the same as normal and should technically be fine.

As for blinding, as long as the pattern is clean and correct and the headlight alignment is setup (might have to be done on some lights after a change) they should be ok.


So, the real question is, what options are practically available and at what price? mainly for the 4g owners, but also for the 5g owners.

D2S/D2R is the fitment of the HID bulb, it's what most German manufacturers use (BMW,VW,Audi etc). This is what me and R8GYY have in our retrofits. I think they are Philips 4300k ones (factory OEM). Basically a projector retrofit is the only way to legally install HID's, which with the right tools & parts can be done in a 4th Gen. It's quite beyond me, hence why i paid big bucks for someone else to do it in my 5th gen!

a question i have is according to your legal document stating that projectors require headlamp washers. i disagree with it and even if it is correct i think most manufacturers are not following it..

1 ) vauxhall corsa's 2007 / 2008 models have projectors but dont have headlamp washers / self levelling features.
2) civic type r's have projector lights and they dont have washers / self levelling either.

the list is endless but im showing these two as an example

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Yes, it seems that due to there being no UK law at all for HID's, that it's up in the air anyway.

One thing you should be careful of though, is finding states models, as their HID laws, similar to ours, with the exception of the self levelling and the washing requirements.


I've also updated the first post with a short video test AutoExpress did regarding the simple HID retrofit kits.

Interesting thread Max. It would seem to me that though there are laws re. projector headlights in place, pretty much nobody is aware of them, including sellers of HID kits etc (either that or they are just ignorant, as you say).

As you know, the legal factor (or lack of!) was one of the reasons I took my HIDs out within a week of use. That and the fact that I was flashed more times in 5 days than I have since I have been driving. Yes, they look the dogs scrotum and are uber bright, but that doesn't mean they are safe, and I dare say there have been a few, if not a lot of accidents related to people using these and blinding oncoming traffic.

the reason we have this problem is simply because the British Standards (BS) safety tests are more strict than the European Union (E mark) ones are, HID's were found to be unsafe by us and failed testing due to something about dazzling other drivers i think, however they passed the safety checks in Europe so were then road legal throughout the EU including GB, its a political clusterfuck tbh

Whilst partially correct ubersonic, it's not exactly the case, we actually don't have any standards on auto lighting since 1988, as HID's didn't exist then, we never passed them nor can we test them as we have no standard to test them against.


As a result of this, we need a UK source of actual headlight units with projectors in them.
Here are the ones i found in the US for the 4g, for reference purposes only really as i don't know if they will work in the UK (dip direction) or whether they'll export to the UK.

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I like those chrome Spyder projectors in that thread. Haven't seen them before

In the broadest terms, unless your car comes with HID headlights from the factory, fitting them in any sense is illegal.





Even doing the best possible option, which is to retrofit projectors & HIDs from a vehicle that had them as standard, is still illegal, but overall it is the best possible thing to do, if you must do anything.


Plonking in a set of "HID" bulbs into your standard reflectors is about the worst thing you can do - the way a standard halogen bulb and an HID bulb generate light is completely different, and the focal points even in the best "HID" bulbs is not in the same place - causing massive amounts of light scatter.



So, to reiterate - DON'T DO IT!!

I have halogen projectors, thats ok right?

still good improvement

Whilst it's still an improvement - it is not legal, as it more than likely won't be E-Marked, and certainly not if you have modified your lights yourself!



My OEM-HID/projector retrofit is not legal, and I fully understand that, however I have made efforts to make it follow the guidelines and regulations as best I can, and all I can hope is that my doing that is enough for me to "bypass" it being an issue - although VOSA will be well within their rights to seize my vehicle should they wish due to the modifications I have made!

I'm sure I risk being ridiculed here but what's the point in changing the headlamps?

It pisses me off that there are so many cars on the road with really bright headlamps. They are blinding when you're driving the other way. What's wrong with using the standard lamps?