At 11:33 AM 3/23/2009, Mike S wrote:
>I use the type 93 bulbs for the taillights, which put out 5 times as
>much light as stock, but only draw 13 Watts.

What's the ratio difference in light output between them and the
stoplights?  If I'm reading FMVSS 108 correctly, the currently
allowed range for tail light lamps is 2-18 candlepower, and at 15 cp
the #93 bulb meets this.  But the currently allowed range for stop
light lamps is *80-300* cp, a minimum ratio of 4:1 and maximum of
105:1. At 32 cp our 1156 stop lamps would only give a ratio of 2:1.

I'm looking for SAE standards J585d and J586c which I *believe*
covered the candlepower requirements for our lights when they were
made, but only finding references to them so far.  But a #89 bulb is
rated 6 cp, which would give a 5:1 ratio stop:tail, so I think the
spirit of the regs is plain -- they continue to want at least a 4:1 ratio.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"