FromDate: Tue, 6 Jun 2000 10:19:08 +0100
From: "Hunter Johnson" <HJOHNSON_at_dbmail.debis.de>
Subject: Re: Euro Lights (long)
Jim E says:
"For some unknown reason (at least to me) the ZKW were never used on the M3
coupe - neither the 3.0 or 3.2."
Jim B says:
"Would the coupe lights be different than the sedan? Just wondering, since
the Euro lights I have on my car are ZKW (purchased from Bekkers Imports,
"I saw some strange lights on Kelly wollenbergs car once. Looked like US
headlights, but were glass. She ordered them when she did euro delivery.
So they arre US dot glass lights. maybe you got one of those..."
The early Euro E36s came with polyellipsoidal low beams, which were replaced
5 years ago with what Jason calls "looked like US headlights but were glass".
The polyellipsoid system works like an overhead projector, with the bulb at the
first focus of the ellipse and the screen which produces the sharp horizontal
cutoff positioned so that the funky semi-spherical lens projects it onto the
road. The "poly" part of the polyellipse means that the reflector shape is two
different ellipses, one shape for the vertical cross section, another for the
horizontal cross section. This way a lot of light is dispersed from right to
left, but not so much dispersal happens from top to bottom.
The newer headlamps are Free Form (Hella's term) which means that a computer
is used to calculate the shape of the reflector given the bulb position and
the desired beam pattern on the road. This technology was used on ALL US E36s,
although of course the ECE and DOT beam patterns are different, so these units
are different. FF lamps are much more efficient than the polyellipsoid system
(if there is a screen, then some of the light is hitting the screen and not
getting to the road), although personally I prefer the Polyellipsoid since
it focuses the light more intensely.
On all E36 headlamps the high beams are probably simple parabolas.
One of the other differences between DOT and ECE lamps is the use of glass
vs. polycarbonite for the outer lens. The DOT has strict rules about the watertightness
of the headlamp assembly, and the ECE lamps often fog up from
poor sealing. However, the DOT lamps' plastic also get sandblasted after
several years of use and this messes up the ability of the light to get out,
requiring replacement of the entire headlamp to return to 100% performance.
The ECE unit's glass outer lens can be replaced for around $60.
The difference between a Bosch, Hella or ZKW headlamp unit designed for the E36
is probably nonexistent, although these suppliers will probably tell you
The fact is, BMW specifies the headlamp beam pattern (at the suggestion of
the initial supplier), and from there on the subsequent suppliers have to meet
this criteria. One exception, however, may be that if ZKW wasn't an OEM
their lamps might be inferior (i.e. insurance replacement but never specified on
Personally I believe that while there is still a difference between the BMW ECE
DOT headlamp, with the next E46 this difference may be non-existent -- about 5
ago I changed the lamps on my 300TE Mercedes-Benz from DOT to ECE and gained
little performance. The ECE and DOT have been working over the past
5 years to achieve a homogenized headlamp pattern for use world wide, and while
not there yet, the ECE pattern now allows more light above the horizontal than
used to, and the DOT lamp has a blend between a simple "hot spot" and a
cut off, and I don't doubt that as the age of the motoring public in the US
to creep up, the DOT will get more and more complaints about headlamp glare,
a more European-style beam pattern in the US -- especially given the advent of
discharge bulbs, which throw twice the light from 2/3 the power.
That said, please keep in mind that a properly aimed ECE lamp (1% drop) has a
60 meters, so at 60 mph you are out driving the range of a European headlamp (60
45 m/s, so 60 m = 1.3 seconds). The DOT lamp which throws light above the
will therefore have a much greater range.
However, I find that the ECE high beams are superior to the DOT highbeams, even
they might be simple parabolas.
John F. will surely want to comment on all this, since both of us live in
but my impression is that neither of these systems are optimal. My
regarding retrofitting ECE lamps to your car is that first try to reaim the DOT
so that the hot spot is directly in front of the bulb, instead of down and to
Also, raise the beam so that the horizontal cutoff is at a 1% drop from the
ECE specification (that is, if the bulb is 60 cm above the ground, and the car
10 m from a wall, then the horizontal line should be 50 cm above the ground).
If that doesn't do it for you, then try the ECE lamps, but I would go the extra
install the Euro spec headlamp adjuster. This has four settings: 0, 1, 2, and 3,
believe that they correspond to the % drop, so "1" is the normal setting. By
your new Euro lamps correctly you can dramatically increase the range of the
moving to "0" on the fly, and dropping back to "1" when you encounter traffic on
highway. The "2" and "3" are used if you have lots of stuff in the trunk, which
your headlamps to shine upwards.
[ Help ]
1998 M3/4 with Euro lamps, no adjuster