I replaced the original Osram D3S bulbs on my 2010 TDV8 a few weeks ago with OSRAM D3S Night Breaker Unlimited bulbs. OSRAM claim significant increases in light output. I did a comparison of the original bulb with the new bulb (drivers side new and passenger side old) using a light meter and at a distance of 15m got an increase of over 50% in light output just below the horizontal cut off line on low beam. Visually you could see a significant difference looking at the lights when turned on and also in the beam pattern on the road.

Recommended.

I've been using these for some time now. Definite improvement when driving on lanes at night. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Same here and also replaced the halogen main beam with a higher color temperature to match the xenons. 2018 Telsa MS
2012 Range Rover Sport HSE+
1990 Porsche 944
1985 LR 90 Soft top V8

Puslinch don't suppose you're able to link the main beam bulbs you have? I'm looking for some that will match the xenons colour

I run PIAA Xtreme White high beam bulbs. They match the low beam perfectly in colour.

Signori wrote:

Puslinch don't suppose you're able to link the main beam bulbs you have? I'm looking for some that will match the xenons colour

Links??? URLS???? pics????

would be nice....

Picture of PIAA Xtreme White Bulbs package, part number H-218

Have a peep at this thread: http://www.rrsport.co.uk/forum/topic46312.html

I'm still running the same bulbs now, haven't had any issues with them and I won't go back to halogens, if you'll pardon the pun; the difference is night and day!

The problem with using LED bulbs in a closed environment (which is the case with the RRS headlamp) is that the fan driven heat exchange function cannot work properly - there is no where for the heat to go in a closed housing. The LED driver gets extremely hot and needs cool air to work properly and give full power. The ability of the unit to operate effectively and over a long period of time will be dependant on how long the lamp is operated continously. If you use it for short periods of time intermittantly it may not be a problem. I don't know of anybody who uses an LED bulb in a low beam application within an enclosed housing for the above reason. Bulbs using a weatherproof seal such as HB type bulbs don't generally get installed within a sealed enclosure, similarly H4 LED bulbs generally use the rubber end cap where the bulb passes through a labyrinth seal. In both cases the heat exchanger fan is not within an enclosure.
I'm not saying an H7 LED bulb will not work within the RRS headlamp unit but it does not make sense to have the fan driven heat exchanger within an enclosure. None of the major LED bulb manufacturers (PIAA, IPF, OSRAM, Philips etc) make an H7 LED bulb as I suspect as they cannot make the bulb/lamp weatherproof without putting it in an enclosure which will not allow sufficient cooling of the LED driver.

There are MANY high power enclosed LED units on the market. Mainly light bars, but OSRAM do an LED fog light replacement, the main reason that the big names don't do LED H7's etc is because there isn't a way to replicate the light in the same position as a filament bulb, so your beam pattern suffers. Also, non of the replacement LED units are E marked so technically they're not road legal (in the UK). I only use them as high beams so I don't dazzle other drivers.

While I agree that the driver does create a lot of heat, the replacement lights have considerably bigger heatsinks than the little t20 replacements you get (which technically don't have any), so while cool air is obviously beneficial, any air flow will do. The headlight units in the sport are massive, thus allowing the hot air to be spread around the unit easily and don't forget that the front and sides of the headlight unit have air flowing across them which provides extra cooling, finaly, while the headlights don't allow direct airflow from outside they do breath.

I've been running the LED units as mentioned in my link for 8 months, I have drive back from London a few times along the A303 at 3am using the high beams pretty much constantly (3 hour journey) and my units are still as good as the day I bought them. So I appreciate your skepticism (I was VERY skeptical of them), these bulbs have been well tested now and honestly, they're the same price as a decent set of bulbs so even if they do fail you've not lost anymore than you would if a halogen fails prematurely.