Re: HIDs

["Graydon D. Stuckey" <graydon@apollo.kettering.edu>]

On Mon, 9 Aug 1999, john r. cummings wrote:

>   I agree with Wolff.  Sorry I don't agree about the merits of HID. I have
> converted my 91  20v turbo 200 to euro lights and my wife has a 99 A6 with
> HID lights. The HID lights make the euro lights seem dim by comparison, but
> that's where the benefit ends. The HID lights skim along the road at about 36
> inches off the ground with no diffusion. They are brillaint where they shine
> but they cut off with a razor sharp line to pitch blackness. Any bump, hill,
> curve,  or change in acceleration or braking changes the angle of the lights

Ahh, but that's not the fault of the HID, but the beam pattern that Audi
(or Bosch? Hella?) designed into the reflector assembly.  The HID is
merely the light source, and the light that it produces must be gathered
and aimed down the road.  If you put HID bulbs in a DOT Audi headlight, it
would be no better than a regular Audi DOT headlight.  But, if you put an
HID bulb in a well designed reflector, you will have superior light.  I
have no experience driving the new A6, so I can't comment on its
abilities, but from your comments, it sounds like the beam may be actually
too sharply cut off.  In a headlight test a couple years ago, one of the
car mags actually noticed that phenom.  They commented that some of the
lights with less sharp cutoffs faired better in peripheral recognition of
objects.  Makes sense to me. 

> and dimensions) so that we can have safe backroad lighting. After 20,000
> miles of driving over the last 7 months you can count us as unimpressed with
> HID lights.

We ran about 12,000 miles in the last 8 weeks in the V8.  :-)  Great 
driving, all of it!  We've been from LA to Princeton, NJ.  It has been one 
of my best driving summers in a long time. :-)

Later,
Graydon D. Stuckey
'91 V8 Quattro 5-speed		'86 Mazda RX7 TII+2
I have a new exhaust systems webpage - check it out at...
http://www.geocities.com/MotorCity/Factory/8023/index.html