LED Bulbs vs. H4 Bulbs in Reflector Headlights


We're far enough along, having completed the Alpha Stage, that we are seeking a number of Beta Testers for the Philips LED bulbs. Let me know if you are interested and we will send you the bulbs free in return for your thorough evaluation. We will also give you an Audette Collection t-shirt. Contact me by using the pop-up "Request Info & Recommendations" form. Program Full - Thank You!


From: John Audette

Our job is to bring you Best-in-Class products, especially with a product as important as headlights and forward lighting.

This is an important issue for Audette Collection customers. If technology has advanced sufficiently to be able to convert to LED headlights from H4 halogen headlights simply by changing bulbs, as opposed to installing new assemblies, that's a big gain. It's simpler and less expensive.

We have been a pioneer in LED headlights for air-cooled Porsches for over 6 years now with the production of our LED assemblies. But if there is an improved way to upgrade to LED headlights it's our responsibility to bring it to you. Testing is underway and we will keep you posted.

According to Daniel Stern, our lighting consultant, both Philips and Osram have LED bulbs for reflector headlights that look promising. He's not quite ready to recommend them yet as he hasn't tested them in various reflector headlights.

Here's a conversation we had:

JA: What is your opinion of the Philips LED bulbs?

DS: They work surprisingly well in a few headlamps…reasonably well in some headlamps…passably well in some headlamps…poorly/not at all in other headlamps.
JA: How do they compare to the Osram?
DS: Different list of: surprisingly well/reasonably well/passably well/poorly/not at all. Very interesting to see the obvious beam pattern differences if you pick out a headlamp and try both bulbs in it, one after the other.
JA: Do you know how they work in generic 7" round H4 lamps as commonly used in Porsches?
DS: No such animal. They work differently in this versus that versus the other Hella 7" round, differently in the three different Bosch 7" rounds, differently in the six different Cibies, in the five different Marchals, the two Carellos, the two Koitos…


We have testing underway. In the meantime, please do not buy the junk LED bulbs from China on Amazon or anywhere else. It's all hype and they are junk according to Stern. I'll keep you posted.


By: Philips Lighting

Why buy the Philips Ultinon Pro9000 LED 9003 (HB2/H4) (Twin)?

With the Philips Ultinon Pro9000 LED range, Philips have harnessed all their experience and world-class engineering expertise in making an LED headlight bulb far in advance of its competitors. The Philips Ultinon Pro9000 is capable of producing masses of extra light, with a beam up to 250% brighter than standard, while also providing supreme style with a striking cool white light colour. As a result, the Philips Ultinon Pro9000 may just be the superlative headlight bulb choice for drivers wanting the utmost in terms of both performance and style.

Utilising state-of-the-art exclusive Lumileds TopContact LED chips, the Philips Ultinon Pro9000 achieves a light performance that is both incredibly strong and consistent. The bulbs' strong projection not only achieves a brightness up to 250% stronger than standard, but a uniform beam pattern, allowing for a sharp, consistent stretch of light – unlike the inferior 'dotted' light effect of many cheaper LED bulbs. And thanks to Philips SafeBeam technology, the position of this huge projection is optimised to provide maximum coverage of the road ahead, while also avoiding dazzling oncoming traffic.

As well as enhancing the driver's vision on the road at night, the Philips Ultinon Pr9000 also offers a terrifically stylish white light colour, with a high Kelvin rating of up to 5800K. And where often such enhanced style and performance comes at a dramatic cost to bulb life, the Philips Ultinon Pro9000 boasts an incredible lifespan of up to 5000 hours. This is thanks to the Ultinon Pro9000's thoughtful, durable design, which implements several patented Philips technologies (such as AirCool and AirBoost) to manage excess heat. All of which work along with the bulb's splash- and dust-proof design, its EMI-compliant engineering and thermal shock-resistance to ensure a massively enhanced bulb lifetime.

For optimal LED light output, style and ease of use, the Philips Ultinon Pro9000 clearly outshines the competition.

Features and benefits

  • 250% brighter than standard
  • 5800K colour temperature
  • Striking, stylish cool white light colour 
  • AirCool and AirBoost heat management systems for longer LED life
  • Extremely long bulb life expectancy – up to 5000 hours
  • Compatible with 12V and 24V electrical systems
  • Sharp, consistent LED beam pattern
  • SafeBeam technology for accurate, far-reaching illumination
  • Simple, compact plug-and-play bulb design


 JA Note: I thought it would be interesting to run this by our new AI friend. Pretty accurate, also pretty plain vanilla which I find is the case with most ChatGPT responses. We have to cut it a little slack though as it hasn't been online in over a year and so it's missed the latest technological advances, such as the evolution of LED H4 bulbs.

By: ChatGPT

Pros of using LED bulbs in place of H4 halogen bulbs in reflector headlights:

 Energy efficiency: LED lights consume less power than halogen lights, which means lower energy bills and less strain on the car's electrical system.

  1. Long lifespan: LED lights have a longer lifespan than halogen lights, which means you will have to replace them less frequently.
  2. Better visibility: LED lights produce a brighter, more focused light beam compared to halogen lights, providing better visibility when driving at night.
  3. Faster illumination: LED lights turn on instantly, while halogen lights take a moment to warm up.
  4. Durability: LED lights are more durable and less susceptible to damage from shocks and vibrations compared to halogen lights.

Cons of using LED bulbs in place of H4 halogen bulbs in reflector headlights:

  1. Cost: LED lights are typically more expensive than halogen lights, so there is a higher upfront cost.
  2. Compatibility: LED lights may not be compatible with all vehicles, so it's important to check before making the switch.
  3. Heat management: LED lights can produce more heat than halogen lights, which may affect the longevity of the lights or the performance of other components in the vehicle.
  4. Light output: Some LED lights may not produce as much light as halogen lights, so it's important to choose a reputable brand with high-quality LED lights.
  5. Installation: Installing LED lights can be more complicated than installing halogen lights, and may require modifications to the vehicle's wiring or other components.

Do LED bulbs in illuminate as efficiency as H4 bulbs in reflector headlights?

LED bulbs can illuminate as efficiently as H4 halogen bulbs in reflector headlights, but it depends on the specific LED bulb and the quality of the reflector design. LED bulbs typically have a more focused and intense light output compared to halogen bulbs, which can result in improved illumination and visibility. However, the effectiveness of the illumination also depends on the quality of the reflector design, as a poorly designed reflector may not fully utilize the advantages of an LED bulb.

It's important to note that not all LED bulbs are created equal, and the quality can vary greatly between different brands and models. To ensure the best possible performance, it's recommended to choose high-quality LED bulbs that are designed specifically for use in reflector headlights. Additionally, it's important to properly aim and adjust the headlights after installation to ensure that they provide optimal illumination and visibility.