[KhaosKid]

I tried these red LEDs for my brake light bulbs after using regular white LEDs (both from Sylvania) and the difference in light output was night and day.

The white LEDs behind the red lens of the brake lights put out less light than stock halogen bulbs, and the light came out closer to pink than deep red in person. I then found out that Sylvania recommends red LEDs for taillights with a red lens.

I didn’t think the difference would be so noticeable, but I was pleasantly surprised. The output is a little brighter than stock output now, and the instant-on feature is good for safety.

The Red LEDs I Installed are the Sylvania Zevo 7506R bulb model/type.

They’ve been installed since end of May 2023, will update this post periodically, as well as if any of the LEDs burn out. I kept the old stock halogen bulbs so that I have something to use during the warranty turn-around period. I’ve never used Sylvania’s warranty before, so will update on that experience if I ever have to.

*The second picture shows the difference in light output of white 7506 Sylvania LEDs (non-zevo) and red Zevo LEDs from Sylvania. The reflection of the red light on the garage floor helps indicate the difference in light output. It’s hard to show differences in light output/intensity because the iPhone 14 (and most if not all others) camera automatically adjusts brightness levels

1st picture is with both red LEDs installed. I hope this helps y’all decide what to buy, as I had no idea you needed to match the LED color to the Lens color.
It’s not something thats necessary when using halogen bulbs so I don’t think many people know that either.


TLDR; make sure you match the LED color to the taillight lens color when switching to LED brake lights, or else the output will be worse than with the stock halogen bulbs (21W bulbs)

Also, stock halogen bulbs (type 7506) output 21w but 3506 output 26w which may not be good for the housing. Despite that, many bulb manufacturers will claim on their websites and/or packaging that 7506 and 3506 bulbs are interchangeable. They ARE physically interchangeable because they fit in eachothers sockets, but I assume the slightly higher wattage of the 3506 bulbs is bad for taillight housings calling for 7506, over time. This may be a controbuting factor towards taillight housing and wiring issues, even though its just a 5watt difference.

[crashoverride]

So timely and great advice I'm needing to replace half the bulbs back there. How many bulbs are needed two or four to replace all..?

[crashoverride]

Now questions Does this fit in the bulb holders which are meant for round glass bulbs..? It appears you put a review up on Amazon (thanks) yet almost every other review says car still thinks bulb is burned out and/or light flickers etc... So lots of complaints

[KhaosKid]

Originally Posted by crashoverride

Now questions Does this fit in the bulb holders which are meant for round glass bulbs..? It appears you put a review up on Amazon (thanks) yet almost every other review says car still thinks bulb is burned out and/or light flickers etc... So lots of complaints

Originally Posted by crashoverride

So timely and great advice I'm needing to replace half the bulbs back there. How many bulbs are needed two or four to replace all..?

You need 4 brake bulbs in total.
The bulbs will flicker so you have to code out the cold and warm bulb checks. I will update the post later with the codes for my car which has an FRM3 footwell module.

Coding out the bulb checks is much better than using the resistor to (hopefully) get rid of the flickers. Because the resistor gets really hot and its hard to find a good place to mount it without drilling into the metal.

Edit: see my post 2 or 3 posts down for the FRM3 codes I modified to stop seeing the bulb-out warnings on the dash AND to stop the flickering of the bulbs during bulb tests.

[lowrydr310]

Originally Posted by KhaosKid

I
Also, stock halogen bulbs (type 7506) output 21w but 3506 output 26w which may not be good for the housing. Despite that, many bulb manufacturers will claim on their websites and/or packaging that 7506 and 3506 bulbs are interchangeable. They ARE physically interchangeable because they fit in eachothers sockets, but I assume the slightly higher wattage of the 3506 bulbs is bad for taillight housings calling for 7506, over time. This may be a controbuting factor towards taillight housing and wiring issues, even though its just a 5watt difference.

Looks great! I may try this upgrade. I'm skeptical of using any LEDs because I don't want any flickering or other issues like I see so much. However Sylvania is a good manufacturer so hopefully they last long. I used Philips LEDs in the license plate bulbs for my E90 and for another car and I've had them for years without issues, so maybe it's just the generic junk that's burning out.

Agree that the 5W between the 7506 (P21W) and 3506 does make a difference and affects the tail light housing, at least for Pre-LCI models. I had a 325 where the previous owner swapped a few bulbs for the 3506 and the housings were melted and bubbling with some cracks from the heat damage. I replaced the plastic bulb holder assembly and swapped those bulbs for the proper P21W bulbs and no more melting or cracking.

[KhaosKid]

Originally Posted by lowrydr310

Looks great! I may try this upgrade. I'm skeptical of using any LEDs because I don't want any flickering or other issues like I see so much. However Sylvania is a good manufacturer so hopefully they last long. I used Philips LEDs in the license plate bulbs for my E90 and for another car and I've had them for years without issues, so maybe it's just the generic junk that's burning out.

Agree that the 5W between the 7506 (P21W) and 3506 does make a difference and affects the tail light housing, at least for Pre-LCI models. I had a 325 where the previous owner swapped a few bulbs for the 3506 and the housings were melted and bubbling with some cracks from the heat damage. I replaced the plastic bulb holder assembly and swapped those bulbs for the proper P21W bulbs and no more melting or cracking.

Thanks for the anecdote confirming the 5W can make a difference over time, it's good to get confirmation about these theories i sometimes come up with.

I think that helps explain some people having rear taillight issues. I want to get that information out to people to be aware that sometimes bulbs that will technically fit in the holder can cause damage! As awesome as forums are for info for us enthusiasts sometimes there are things everyone accepts but that we got to call out for each other.

[KhaosKid]

Now questions Does this fit in the bulb holders which are meant for round glass bulbs..? It appears you put a review up on Amazon (thanks) yet almost every other review says car still thinks bulb is burned out and/or light flickers etc... So lots of complaints

Sorry for the late reply/update. I finally got the time to code out the bulb-out warnings from my car this weekend.

I have an FRM3 module, and I coded the following out for my brake lights to stop flickering.

kaltue_bl_m2_43_m2_9
aktiv to nicht aktiv
warmue_bl_m2_43_m2_9
aktiv to nicht aktiv

After the above coding, I had one out of two of the brake lights on the left, and the same on the right, flickering on and off instead of all 4. So, then I went back and tried coded the following:

warmue_bfd_m1_5_m1_37
aktiv to nicht aktiv
kaltue_bfd_m1_5_m1_37
aktiv to nicht aktiv

but at the same time I also coded the following, to ensure I don’t get false-alarm bulb-out warnings from using the brakes normally. (Fehlermeldung means error message in german).

fehlermeldung_CC_BL_L
aktiv to nicht aktiv
fehlermeldung_CC_BL_R
aktiv to nicht aktiv

And then I got my assistant to confirm that I got no brake light flickering on start up, as well as no bulb-out warnings on the dashboard cluster for the brake light bulbs.

I hope this helps others with the FRM3 module get rid of that flickering and those annoying false bulb-out warnings caused by LED bulbs .