As I remember, for a long time any car sold in the US was supposed to have individual sealed beam headlights, which is the reason why US market pre-face lift XJS all feature the four sealed beam lamps. I believe that in the US the sealed beam headlights rule was lifted some time in the early nineties. Meanwhile, back in the UK I believe this was not the case, yet I see lots of UK XJS pictures featuring the sealed beams. So, how did this work for the UK? With what kind of headlights were the XJS cars originally sold in the UK and from when to when? Or, was this a customer choice or, perhaps, even aftermarket mods?

 

Until the law changed in the USA, all US versions had the twin headlights. In the UK all cars were fitted with the one piece headlights with individual removeable/replaceable bulbs. But now, in the UK and many other markets, the one piece headlights are NLA, but kits for the twin headlights (not sealed bean, but with removeable/replaceable bulbs) are available easily, if somewhat expensive. Hence you see many cars with the twin headlights, which are a standard European size and available very cheaply, as they were used on loads of EU hatchbacks, family saloons, etc etc.
Interestingly, the TWR racing XJSs used the twin light setup as it gives better night time illumination.
Greg

 

I have the 4 headlight kit on my '92. I personally think they look better that the one piece headlight. I use H4 on the outers and H1 on the inners. I find the lights work better so. But everybody has a different tast.

 

Yep, Greg put it right. Quad lights are often associated with a more sporty vehicle. Example the Triumph Herald vs. Vitesse. Vitesse was sporty, had quad lights. The Golf GTI has 4 headlights in it's sportiest incarnations.

Also, sealed beams were and still are illegal in most European states. So what may look like a sealed beam is actually a directional (asymmetrical) round headlight with H1, H4, H7 bulb which can make illuminating the roads a lot better. The US sealed beams are leathal (I was able to compare them in my Volvo days. Volvo 740 US model with the 4 square sealed beams from Wagner vs. the square Hella H4 units - like day and night!).

 

Thanks for the info, gents. Uh, Daim, can you clarify as to how "The US sealed beams are lethal"? Also, why are they illegal in Europe?

Personally, I see the twin headlights to look more at home on the pre-face lift body style. By the same token, I see the one piece headlights much more in place with the more modern face lift body style.

I couldn't see my '94 front to be the same anymore with twin headlights, especially if you see what I've done. In fact, if you look at sports or sporty cars from the early 90's and up, you do not find cars with twin headlights and if you were to install twin headlights in some 90' and up sporty cars they wouldn't necessarily look "in place". But, hey, this is a matter of taste and XJS cars with twin lights look just fine, if slightly dated (again, to my taste).

Cheers,

 

Well, they are illegal here, as they have a symmetrical beam. The illumination is also rather bad. I was shocks as by how bad they really were. Makes me wonder why you over there were force to use them.

 

 

It was originally designed with Cibie H4 units, as all European cars received unless opted for quads...

 

Hmmm the '95 didn't have sealed beam quad headlight, it has the one piece Euro headlight. I believe some came with glass fronts and later ones with plastic fronts. Both kinds take H4 bulbs accessible from a removable panel in the wheel arch / fender .

The main problem with US sealed beams is that they not only don't dip to the side they also have a much lower wattage than H4 bulbs.

My '92 MY with wires, quad headlights and a small leaper, which uses the same holes as the growler so l can change out at will..:-)

 

 

Yeah, which are not the sealed beams you think they are. Sealed beams mentioned here are the small round units, as fitted in the quad headlight setup. What you are calling sealed beams are actually just plastic Cibies You can change the bulbs... So no sealed beam. That is why they are better

 

In Europe many of the overhead sign on highways/motorways are lit, so there is no need for the headlights to illuminate them. The European pattern lights put all the light down onto the road and have a very sharp upper cutoff, so as not to blind oncoming drivers. That way the lights can be bright, but friendly to other traffic.

The US sealed beams in contrast were designed for US highways where the overhead signs are not lit, so the lamp was designed to spray light upward to light up the signs. Unfortunately, that light that is aimed upwards will also blind oncoming drivers, so the lights are much lower wattage than the European lights - typically 35W vs 55W. The US lights take the much smaller light output and then spread it around, so only a tiny fraction is on the road compared to the European light that takes more light and puts it all on the road.

Note the distinction between a sealed beam and a European lamp. In the sealed beam the entire assembly is replaced when it burns out. The European lamps have a lamp housing with removable bulbs, so when the bulb burns out only the bulb is replaced, not the entire lamp assembly. There are common round lights in European patterns, typically called H4 lamps, because they take an H4 bulb. It's a replaceable bulb type though, and that's what the XJS one piece lights are - replaceable bulb, not sealed beam.

 

how do the newer HID, High Intensity Discharge , lights fit into this debate??

 

The US regulations have changed to align with the European ones, so the light now goes down to the road. HID's would be impossible under the old US regulations, as every oncoming driver would be blinded by the bright lights.

 

HID lights are, I believe, illegal unless allied with a self levelling system. This to avoid blinding oncoming drivers as HID lights are so much brighter.
Having said all that, aftermarket HID kits are made so that the light emitting unit fits into a standard reflector unit. So for example, and H4 reflector unit that is made to take an H4 bulb, can also accept an aftermarket HID light emitting unit with an H4 fitting pattern. HID dipped light in such kits to replace H4 bulbs is achieved by physically moving the light emitting unit to give light to the dipped-light reflecting part of the reflector.
FYI, H4 bulbs are twin element main beam and dipped beam bulbs, these are used in the outer of the twin units. H1 bulbs are single filament high beam only bulbs and are used in the inner main beam units on the XJS. The inner and outer reflector units are not the same. The bulb fitment part of the reflector is different and an H4 will not fit an H1 unit and vice versa.
The main reason the twin units give more light is because on main beam there are 4 elements giving light: the two inners and the main beam element of the two outers.

 

 

Vee
I do not quite follow. Main beams are high beams. If you mean the outers are only the dipped beams, then you maybe you stilll have the original sealed beam units - these do not allow twin filaments - or maybe the USA spec headlight wiring setup is different. I am pretty sure the UK spec facelift H1/H4 twin light (non sealed bean) setup has all four powered on main beam. Could always be wrong, of course!

 

 

Well described there Jagboi. But, very very fee roadsigns be it high way, urban or rural are illuminated. Spoken for Germany: no signs are illuminated. But they are placed most commonly to the right of the road, where the asymmetrical pattern will illuminate them properly.

@ron

HID are a to pic for themselves.

- 25W and 35W are to de differentiated

35W requires, globally, automatic height adjustment AND headlight washers (high pressure jets).

25W does NOT require AHA and HW. BUT then the light is a worser quality.

 

I was not aware that there are two types of "Quad" lights: the sealed lamp assy and the not-sealed Euro lamp. Is there any trick to distinguish one from the other by looking at car pictures?
Also, is then my understanding that with the American version, i.e. the sealed beam, you replace the entire assy whereas on the Euro Quads you can actually replace the light bulb itself and leave the rest of the assy alone. The weird thing I'm hearing, however, is that the American sealed beams do not have a safety height cut-off of some sort, as not to blind the upcoming traffic for the sake of illuminating road signs? Wow, really? BTW, the highway signs I see here in CA are all illuminated, but still, it is hard to believe such an irresponsible decision from the DMV to approve lights that shine in all directions, hmm.