Re. Lights

["Chris Blumenthal" <chris@wallaby.corp.sgi.com>]

I have several comments (maybe, 4 cents worth) about the recent "Lights"
thread.

You can only get 35W of "power" (the correct description of what is being
measured by "watts") from a 35W bulb. You may, however, get differing amounts
of light (usually measured in candlepower) from different light designs using
the same bulb design and wattage. Thus, the new lights using computer designed
refractors and focusing lens put out a heck of a lot more light than legacy
designs.

There are no magic bulbs that have the same wattage, but put out differing
amounts of light for the same application.

Lights designed for the US market must use the D.O.T. approved, limited wattage
bulbs (the 9XXX series and the like). During the last year or two, the DOT
style halogen bulbs have been appearing in the aftermarket in higher wattages.
It is not worth trying to put these bulbs into use with stock wiring and
connectors; you will not get the benefit of the extra power, due to the
limitations of the wiring and connectors, and you will fry your connectors.
However, the same people who sell the bulbs will sell you a wiring harness with
new, heavy duty connectors. This setup is at best a compromise when compared to
euro lighting, because the lights do not seem to be able to take much advantage
of the extra light produced, due to braindead refractor and lens designs. BTW,
the US version '96 A6 has vastly improved lights (two spherical lenses on each
side for low beam and "fog light" and decent high beams, all using the low
wattage DOT bulbs.

The DOT bulbs were created so that the car designers could have freedom of
design in lights (and thereby create some of the worst auto lights in history)
in order to keep the hood profile flat and more aerodynamic.

The euro lights (and most fog or driving lights sold in the US) have continued
to use the H1, H2 or H3 style bulbs. Usually, an single high beam uses an H1
bulb and a high-low light uses the H3, which has two filaments. 100W H1 and
90/130W H3 bulbs are fairly easy to source in the US (the lower wattages [55W
H1 and 55/65W H3] are still legal for "offroad" use and use in motorcycle
lights).

The optimal setup for almost any audi is the euro style light. It is almost
impossible to find such lights in the US for the 5K turbo, which has the lower
hood profile, and the lights are very expensive ($750-1000). This is quite a
nice setup, however, using H1s for the inner, high beam, and H3s for the outer
high/low. Also comes with a "city" light, required in many European cities now,
and provisions for servo controlled light aiming (realtime adjustment on the
highway...!). However, the alternate style of light (I believe that it is an H3
setup) is more readily available for non-turbo 5Ks and the newer 80s, 90s and
100 series.

The appropriate hookup for higher wattage headlights or auxiliary lights in the
5K is indeed the jumpstart post on the right of the engine, through an
appropriate relay setup.

There has been a lot of discussion about "sealed beam" vs. "non-sealed beam"
lights at the DOT through the years as to why the round or rectangular H1 and
H3 lights could not be used on US roads for many years, but this seems like
bullshit to me, given the move to non-sealed beam lights in the US. It is true
that H1-H3 lights must be carefully and properly sealed in order to keep dirt
and moisture out, but modern designs make this easy.

A final point of trivia is that the road signs are mounted at different heights
in Europe vs. the US. The H3 low beam has a flat cut-off that will illuminate
road signs in Europe, which are lower to the ground, and will not usually
illuminate US signs, which are mounted higher off the ground.

Chris Blumenthal