Sucker? All I said was "Xenon bulbs burn much cooler than conventional
bulbs." That is a fact, just like a 40 watt neon is cooler by far
than a 40 watt incandescent. Of course they draw the same amperage. TG
First, I'm pretty sure that any incandescent bulb of a given wattage will
*generate* identical heat to any other incandescent bulb. (I might be wrong
here -- The heat generation could be different if different filament
materials are used. But to the best of my knowledge, all modern
incandescent bulbs use a tungsten filament.) But the different immersion
gases that might used in different incandescent bulbs might have different
thermodynamic properties, meaning that one gas transfers heat from the
filament out to the glass (and therefore out of the bulb) faster than
another gas. This would cause one bulb's filament to run cooler than the
other, despite *generating* an identical amount of heat. (The same way a
heater creating "X" BTU's of heat will keep an insulated building warmer
than a non-insulated one.) And it is the filament's temperature that by and
large determines the temperatures at the electrical connections to the bulb.
(Though the thermodynamic properties of the bulb base material and the
electrical conduits inside it also play a small part.)
But I think what Ned was referring to wasn't the actual bulb temp so much as
the temp of the wires supplying power to the bulb. *This* temperature is
directly related to the current passing through them and nothing else. And
for a constant voltage, a higher-wattage bulb *must* draw more current, and
therefore must generate more heat in the wires that supply it. The only way
to draw more current through a wire without generating more heat is to
replace it with a different wire -- either of a larger gauge or a less
resistive conducting material.
Secondly, putting genuine HID bulbs (and I've seen "Xenon" used to label
both
real HID lights *and* incandescent upgrade bulbs) into reflectors designed
for incandescent bulbs is both annoying to other drivers and potentially
dangerous for you. Such kits do exist, but should not be legal. The only
safe HID conversion is one that includes new reflectors. (See
http://www.danielsternlighting.com) I don't know whether the "Xenon" bulbs
to which you refer are actual HID bulbs (complete with a high-voltage
transformer) or just fancy-named incandescent. But your remark about
drawing less current (which real HID's do) caused me to suspect the former.
Thirdly, putting over-wattage bulbs in your car is extremely *selfish* as it
improves your night vision to the detriment of everybody else on the road.
Running over-wattage bulbs is roughly equivalent in driver courtesy to
refusing to dim your high-beams for approaching traffic. It makes the
statement "I can see better and I don't give a damn what price you're paying
for it." I'll grant that there are some poorly-designed headlights out
there that just don't do a good job of illuminating the road. But these are
by-and-large aiming and dispersion pattern problems. And they're not a
legitimate excuse to make the rest of us suffer.
The headlights in my wife's old Mercury Sable station wagon both blinded
approaching drivers (even on low-beam) *and* did a poor job of illuminating
the road (even on high-beam). The bulbs threw out plenty of light, but none
of it seemed to hit the road -- it was all aimed too high. And no amount of
adjusting seemed able to alleviate these problems. So while I was confident
that obstacles (like deer or people or other vehicles) would have been
safely illuminated had they jumped out in front of the car, these lights
made driving at night very discomforting, because you couldn't see the
*road* very well.
Had we decided to replace her car's bulbs with over-wattage versions, we
might have improved my wife's ability to see the road at night, but we'd
*definitely* have worsened the blinding of approaching drivers. I
considered, but eventually rejected, the idea of adding driving lights,
because they would have worsened the already-bad blinding of approaching
traffic. (Which, BTW, is also dangerous in addition to being rude.) So we
just lived with it until we got rid of the car. We eventually gave the car
to my wife's sister, who's managed to avoid getting into any night-time
accidents with it so far. But I'm still optimistic.
If I had it to do
again, I probably would go ahead and install some auxiliary lights that were
aimed nice and low, so as not to badly affect approaching traffic while
still illuminating the road directly in front of the car. But I will never
install over-wattage bulbs in any car, nor will I abide those who do.
- Greg Reed
