Brightness of lights - a question, not a whinge

[AW111]

Ok, so there already a brake light thread for bickering on here: http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I have a question : is there a regulation / design rule that relates to the light output of lights (including indicators etc)?
The bulb sizing by power, eg 21w for brakes, works fine with incandescents, but a 21w LED is a whole different kettle of fish.
Similarly, I am not supposed to run 100w halogen headlights, but 60w HID or laser headlights are much brighter.

TL;DR; Does anyone know if car manufaturers have a limit on light output or intensity?

[AW111]

Jader1973 said:

Yes there is. The relevant ECE and FMVSS regs have rules for visibility and luminosity.

Ok, thanks. I knew there we regs on veiwing angles and minimum visibilty, I wondered if there was a max intensity, and if so, what it is.

[AW111]

996TT02 said:

A detail perhaps, but you are unlikely to encounter a 21W LED.

True, but technically I could fit 4 x 5w crees in each brake light, and cause PH to melt down if ever a member was behind me when I stopped.

Then again, I think the LED headlights are around 20 watts. A pair of them on the back, and one in each indicator should do it.
I'll keep the 5w crees for tailights and parkers.