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      10-05-2019, 12:38 PM   #7
3002 tii
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Drives: Z4 M, X5, GX460
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Quote:
Originally Posted by Residentj3553 View Post
I'd like to know as well!
Quote:
Originally Posted by WickedNy View Post
Ditto
I'll try to summarize what I learned when researching bulb replacements...

Cliffs Notes
1. In general any bulb that takes on a "wedge" style (T10, 168, 194, etc.) can be upgraded to LED w/o errors.
2. Most of the interior bulbs use 168/194; the only exception is the coupe's trunk which uses festoon.
3. LED replacements for bayonet style are harder to come by so you'll likely need to buy 'no-name' product made in China off eBay or Amazon.
4. If upgrading your bayonet bulb, be sure to pick a LED bulb that has forward facing light output. A lot of the newer LED have chips embedded on the side only and rely on the surrounding reflectors.


Interior
As mentioned above, all the interior bulbs with exception of the coupe's trunk, use wedge style bulbs. Try to go with 168 as they are brighter than 194 but you may not even be able to tell the difference TBH. Color wise, upto you but I actually prefer a soft white (4000K) for ambient lighting and only use 6000K for areas like trunk, glovebox, and console.

For the 3 dome lights, the spacing is really cramped so a typical 168/194 led may NOT fit in there easily. I got lucky and found that the Philips X-tremeUltinon fit perfectly. The regular Ultinon LEDs are cheaper so you could get away with those for the other lamps.


Headlights
Corner lights take on W5W, so any 168 or T10 should do. 194 would work as well but 168 is closer in terms of wattage. I think these bulbs can be upgraded to LED w/o warning errors but I am not entirely sure.

Angel eye (inner halo) uses a 5W incandescent BA9S that's integrated into bulb holder. Plenty of threads cover how to replace it but this is one of the bulbs that WILL trip an error. I was able to disable the voltage monitoring using Carly.

Turn signals take H21W (or BAY9s). The difference between this and the halo bulb is how the tabs are positioned on the base. BA9S tabs are positioned directly across from each other (180 degrees apart), whereas the spacing on the BAY9s are obtuse (120 degrees apart). These too will result in error unless coded out.




Tail Lamps
The parking/fog light is H21W or (BAY9s), same as the turn signals just mentioned above.

The reverse light can be upgraded to a 921 LED. I replaced this with the Sylvania Vevo 921 and thought it turned out great.

The brake light is P21W but there seems to be a lot of confusion as to whether the 1156 or 1157 is the correct LED equivalent. But 2 things I know are 1) our brake bulb is single filament and 2) the tabs are spaced 180 degrees apart but their vertical positioning is offset. Based on the diagram below I think you can rule out 1157 (bottom right) and assume 1156 (or BA15S) is the correct application.



Only reason I’m not entirely sure is because there’s a review on Amazon from a fellow Z4 owner who mentioned some minor modification to the socket was necessary. But if I had to guess he was trying to fit the 1156 in his turn signal socket...

The turn signals use a PY21W. The Y stands for yellow and it’s very similar to the P21W except the tabs are spaced 150 degrees apart. Therefore I think you need to find a BAU15S (or 1156PY) bulb (upper right above).
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Last edited by 3002 tii; 10-06-2019 at 06:18 PM..
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