[no subject]

PIAA's wattage equivalence claims ("55w = 85w", etc.) are utterly false. They
cannot be verified with proper laboratory equipment, and they CERTAINLY aren't
true when compared with real overwattage bulbs on the road. These bulbs have a
purplish-blue coating. They make your headlamps look very "ice white", that is
true. However, they *reduce* the amount of usable light produced by the
headlamps. It is a mistaken notion that "whiter" and "yellower" qualities in
the white light of a headlamp have any direct link to the amount or usability
of the light. PIAA capitalizes on that mistaken notion to sell their bulbs. I
might add, their bulbs are overwhelmingly too expensive, considering the short
life. 
The laws of physics are the laws of physics. They don't bend even for PIAA's
advertising department. There is no way to get "85 watts of light for 55 watts
of electricity", unless the light meter you use happens to go spastic when hit
with blue-tinted light. There is no seeing advantage to these "Superwhite"
("ultrawhite", "hyperwhite", etc.) bulbs, and quite often a disadvantage. They
aren't as bad as the "ion blue" junk used by poseur kids who want to pretend
they have HID headlamps, but they're not magical. And after all that, if you
still want to play with 'em, I have a set of PIAA SuperWhite 80/80w ("light
equal to 135/115w") H4 bulbs for you. This "on road test" pair came out after
two nights' use, and my German 100/90w bulbs went back in so I could see
again. 

Remember the old saw: If it sounds too good to be true... 

I hated having to spend $70+ on a product I knew was crap from the outset, but
I hated worse the idea of BSing instead of giving facts obtained through
actual testing. 

I guess about the only way the PIAA wattage equivalence claim could POSSIBLY
be true would be if they're comparing a 55W halogen bulb to an 85W non-halogen
(tungsten) bulb. All halogen bulbs burn brighter, for any given wattage, than
all tungsten bulbs. The PIAA claim is made in the implied context of
comparison to other QH bulbs, not to incandescent 55w bulbs. Perhaps this is
the inference they hope (with good success) that consumers will make. Perhaps
the "wattage equivalence" claim did indeed result from a comparison with
tungsten bulbs. If so, it would change PIAA's offense from false advertising
to misleading advertising. 

The PIAA literature also talks a lot about "Xenon gas", with the implication
that this is used instead of "halogen" gas. Nope, *all* halogen bulbs contain
a proportion of Xenon gas in the fill mix. There's no such gas as "halogen";
the term is a generic reference to a class of elements. Some constituents of a
typical fill mix are Argon, Xenon, Bromine, and Iodine. (remember when QH
lamps were called "iodine" lamps? That was no more accurate than calling HID
headlamps "xenon" lamps.) There are no halogen bulbs with 100 percent Xenon as
the fill gas, because this causes extremely short filament life by interfering
with the even redeposition of condensed tungsten back on the filament coils.
The coils become "bridged" with globs of tungsten and the filament gets
"shorted out", while other areas grow very thin and eventually melt, failing
the bulb. To a limited extent, fill gas can be tweaked by *slightly*
increasing the Xe percentage and increasing the (already VERY high) gas
pressure to increase the color temperature, but this has a very easily reached
physical limit. 

The "higher light color temperature" trumpeted by PIAA is created by a
purplish-tinted glass bulb globe. It's not a dichroic coating like the
"diamond blue" junk, but it is a tint, and as such physically must subtract
from the available light. Remember, color temperature is independent of the
amount of light, and there is absolutely *zero* evidence that light of a
higher color temperature is better than light of a lower color temperature for
driver performance at night. 

People seem to have the notion that the eye is more sensitive to light of
higher color temperature. This is probably as a result of claims made by car
salesmen trying to push HID headlamps more than anything else; it's false. The
eye is not more sensitive to the blue cast created by the subject bulbs. There
have been several studies done showing improved driver performance (due to
improved vision at night) with headlamps of LOWER color temperature (less
blue, more yellow). Color perception is much better under lower color
temperatures (within the IEC "white" boundaries, of course), and the acuity of
the human eye is really quite lousy under light colors that even begin to
approach "blue". 


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