Wayne H. Francis writes:
> On the subject of headlights, what constitutes a legal headlight
> any more?
A few months ago I actually took the time to browse the US Code (via the
WWW; I forget the URL...) regarding automotive lighting. It's overly
detailed, but the skinny regarding headlights in today's US of A is:
- they must have the three aiming nubs molded into the lens
- they must have the letters "DOT" molded into the lens
- they must meet minimum candlepower (that's right, candlepower. The
spec doesn't reference watts, but _candlepower_!) requirements.
The first replaceable bulb system introduced in the US was the 9004
bulb, which is essentially the same as the "bulb" inside a halogen
sealed beam. Typical 9004 lamps use the same sorry lens pattern as the
sealed beams also. Not an improvement over sealed beams, IMHO.
Recently (1993 or so, perhaps) certain imported cars began arriving on
these shores carrying lamps using the 9003 bulb. 9003 bulbs are also
known as HB2 or, in Europe, H4! So, after all these years, legal H4
systems are finally lighting American roads.
Most of the credit for the razor-sharp low beam cutoff of the H4 systems
is due to the actual bulb design. The low beam filament has a small
reflector next to it that directs all of the light to exactly half of
the reflector, throwing the light DOWN on the road and not UP into the
trees. The lens shapes this light a bit, but it's the bulb that ensures
that no light is "scattered" up into oncoming drivers' eyes. The 9004
bulbs do NOT have this feature, BTW, which is why they still project a
harsh glare to oncoming drivers.
The Hella Vision Plus, available since 1994 or so, is a DOT-legal H4
(HB2) lamp available in 7" round and 6"x8" square configurations. The
lens pattern is slightly different, but anyone wanting H4 performance
with DOT legality should look into these lamps (you'll pay a small
premium).
In today's USA, the ONLY reasons E-code H4 lamps are not legal are the
lack of aiming nubs and the lack of the "DOT" inscription on the lens.
Every other aspect of the technology is legal and currently utilized.
Lots of people run E-code H4 lamps with absolutely no hassle from the
constabulary. As far as I'm concerned, any cop who tickets a driver for
having lights that are TOO SAFE is an idiot.
--
Todd Mullins
Todd.Mullins@nrlssc.navy.mil On the lovely Mississippi (USA) Coast
'74 MGB Tourer with illegal lights
"I could go at any time..."
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