What's the deal with LED light bulbs as side lights and indicators ?
 

Is there such thing as a road legal LED light bulb that can be installed on a car that was not designed to have LEDs from the factory, eg Scoobies.

I see you can now get LED filament lights so they are the same 'design' as an ordinary incandescent light.

What makes them not road legal or not 'E' marked?

Well, you can defo get 501 sidelight filament LED bulbs:

http://www.halfords.com/motoring/bul...rade-bulbs-x-2


But appears they're not legal (yet):

"For interior and off road use only."

^ Exactly, I saw those the other day and figured these must be a legal LED alternative but on the reverse of the packet - as you said - they're not road legal...

But the question is why?

Dunno.

TBH, I very much doubt that you'd get pulled.

I run regular Cree LED bulbs all round (but not the headlights, front indicators and tail/brake lights).

So far, no probs with the fuzz.

Do you know what indicator bulbs the blob uses I'm after some silver ones

I'm not 100% sure but I think they are known as WY21W type but you better check.

Edit - Or maybe they're known as T20 also.

Right, so what benefits do these LED filament bulbs have over the the regular SMD LED types?

Is it simply more even/diffuse illumination?

Yes but they dont work.

Smd are a one directional light source only. That is still an SMD led but enclosed in a cap lamp, so has the same problem.


The reason led sidelights etc arent road legal is because of the one directional light, they do not use the reflectors of the headlight to spread the light but emit it straight forward in an uncontrolled manner.

The reflector shapes the beam pattern and angles it appropriately for the road, and normal filament lamps emit a 340degree beam as opposed to a 100ish degree beam on an led.

The new bmw etc with led lights actually have the led pointed towards the rear of the car and then use the reflector to send the beam out of the front of the car...

So looking closely at the LED 501 bulbs from Halfords linked above, the light is emmited up/down and forwards but not back towards the base of the bulb. Also meaning no light is emmited back towards the reflector?

So the 'filament' is not a true 360 degree light emitter.

That is correct. It is just a SMD in a standard style lamp. The light is emitted straight forwards in a 100° beam.

The cap over the top will help diffuse it, but it still wont utilise the reflector, there is proper led filament technology out there now, just not for cars....

I swapped all of mine over about two years ago to LED bulbs, never had a problem with the old bill or MOT time.


Regarding the indicators I had to swap the relay under the steering column as the wouldn't flash on the normal one but other than that a straight forward swap over.


Cheers
Mark.

Got it! Makes perfect sense.

Thought it looked a bit gimmicky, TBH.

Cheers lads.

I use PIAA led side light bulbs, never had an issue at MOT time.

https://cimg5.ibsrv.net/gimg/www.sco...b832f98bcf.jpg

I'm running Philips X-tremeVision headlights (but SMDs in the sidelights).

Had Osram Nightbreaker H/Ls before that (in fact, still got them - in my tool bag in the boot lol).

Philips say these give a 360 degree light spread????

http://www.powerbulbs.com/product/ph...t10-4000k-twin

Still not road legal...

Yeah, realise that, was just wondering about the fact they are meant to be 360 degree spread, which would negate the issue mentioned earlier????

I had ordered a set, will see what they are like when they are in.... ;)

I saw these myself but didnt get them as I read a few reviews where people said the cap came off and fell into the light enclosure which without removing the light would be a royal pain the ass to retrieve.

Some said to add a bit of glue around the seam where the cap meets the body to help avoid this happening. No idea if this is effective though.