On 25/01/2012 16:18, Dave Plowman (News) wrote:
In ,
wrote:
ISTR Rover making a car with twin headlghts that worked as individual
units. Big problem when driving in snow when the non lit main or
dipped beam would get covered in snow without the heat of the light to
keep it clear. Switch from dipped to main beam and instant darkness.

My Cortina Mk3 had twin lights, but IO never cam across that particular
problem. But then, we rarely had snow in Surrey in those days. I
rememebr driving in snow at night but that was after it had stopped
snowing. (Leaving TVC at 3am having last seen outside at 11am when it
was a lovely day!)

I had several Rover P6 with twin headlights, but the outers were double
dipping and the inners *added* on main beam. Can't think of any other
Rover with individual twin headlights apart from the federal spec SD1.

BMW also made lots of models with individual twin lights, so I can't see
it being a problem given the weather found in Germany.

The four headlight design was necessary because the first halogen bulbs,
type H1, were single filament, non-dipping. That meant you needed one
pair of main beam lights and one pair of dip beam lights. The
twin-filament dipping H4 bulb did not come out until much later, after
which it was, as you say, used in the outer pair.

Colin Bignell