LED rear bulbs...

[Rob_the_Sparky]

Carrying on from the Rear number plate light conversion thread below there was comment about LED bulbs. Now I can see plenty of suppliers of cheap ones but these guys look OK: http://www.autobulbsdirect.co.uk

However, they do a range of LED bulbs that fit with widely varying light intensity. I've seen some boasting that their LED bulbs are as bright as a headlight - this to me is a bad thing...I don't want to be blinding everyone each time I use the brakes, just want decently bright lights. Anyone know what the light output of a stock 21/5W bulb is to compare with the LED ones? Has anyone tried some of these and can comment?

[mk1fan]

Rear brake lights and fog lights are 50W jobbies in incandescent bulb ratings so need to be similar performance in LED for. Rear side lights tend to be 5W in incandescent bulbs so prop rata for the LED.

[Dominic TVRetto]

Do you need to make any wiring changes if you switch the incandescent rear bulbs out for LED's..?

[Rob_the_Sparky]

Nope, but not sure LED indicators will work as I believe the flasher relies on the current draw to control the rate. The CAN bus ones might be OK but I have not tried either yet. I was most thinking about the brake lights as they are the most important.

[mk1fan]

Swap the indicator relay for an LED version. Then there is no need to mess around adding resistors etc....

Although a pain as it means carrying more spares, using coloured LEDs (red for tail, amber for indicator) is sensible as less 'light' is lost through the colouring of the lens.

[blitzracing]

The LED technology varies significantly- the small auto bulbs tend to be surface mount LED's where you have multiple mini LED's on a circuit board(s) to allow light to shine in all directions. The light output will depend on how many LEDs are mounted, and this varies a lot by supplier. You cant simply say you need the equivalent to 50 watt incandescent as you would need to work out the equivalent in Lumens when facing the rear of the car- but on the whole LED bulbs are simply brighter so you dont have too much to worry about. In terms of current draw, its far lower than incandescent bulbs, which wont matter one bit for brake and tail lights. Some of the cheap LEDs on Ebay are over driven at 12v to make them bright so dont last that long.

[David Beer]

The brake lights are 21 watt, the sides 5 w I went led many years ago but went four side lights, double brightness when braking plus a central led strip in the gap between the boot lid.