Obviously the main bulb draw these days is to use LED's, so there's a huge market for them, all kinds of costs, CANBUS support, etc. I ran across a really terrific posting about the 921 light bulb typically used for reverse light applications, over on the Tacoma World forum. The OP studied 7 different bulbs, from incandescent to LED. Results were pretty astonishing. Now, for most people a workable LED (no CANBUS error) will be better than the original incandescent 921, as long as it's at least 500 lumens. But... why stop there?
The "winner" of the shoot-out was the Osram 35w GY6.35 bulb. It wasn't originally meant as an automotive bulb, but it works. At least the folks on that forum (and on Amazon reviews) state they've installed it with success. Extremely bright. Given the limited run time (only on when going in reverse), and relatively cheap cost ($6 per bulb) it seems to be the logical choice. I'm wondering if anyone here has installed such a bulb on their VW/Audi.
My only concern with this, is the fact that the bulb is 35W and would most likely generate a lot of heat. Considerably more than the original 921 incandescent bulb. Now, it may not be an issue due to the short bursts of runtime, but OTOH I wonder if it's something that may be "inconspicuously" damaging. Meaning, that the heat generated may not be enough to notice anything wrong up-front, but I wonder if repeated use over time may start to cause deformity to the plastic bulb socket housing. I know from personal experience that this is possible to happen, under the right circumstances. My Audi A3 had a license plate bulb fault at about 5 years into ownership, which was due to the bulb socket mounts melting. The engineer who designed the license plate light & latch button assembly didn't properly incorporate venting, so the heat buildup eventually compromised it. So... it's possible to happen (I replaced with LED's about 6 years ago and it has been fine since).
The "winner" of the shoot-out was the Osram 35w GY6.35 bulb. It wasn't originally meant as an automotive bulb, but it works. At least the folks on that forum (and on Amazon reviews) state they've installed it with success. Extremely bright. Given the limited run time (only on when going in reverse), and relatively cheap cost ($6 per bulb) it seems to be the logical choice. I'm wondering if anyone here has installed such a bulb on their VW/Audi.
My only concern with this, is the fact that the bulb is 35W and would most likely generate a lot of heat. Considerably more than the original 921 incandescent bulb. Now, it may not be an issue due to the short bursts of runtime, but OTOH I wonder if it's something that may be "inconspicuously" damaging. Meaning, that the heat generated may not be enough to notice anything wrong up-front, but I wonder if repeated use over time may start to cause deformity to the plastic bulb socket housing. I know from personal experience that this is possible to happen, under the right circumstances. My Audi A3 had a license plate bulb fault at about 5 years into ownership, which was due to the bulb socket mounts melting. The engineer who designed the license plate light & latch button assembly didn't properly incorporate venting, so the heat buildup eventually compromised it. So... it's possible to happen (I replaced with LED's about 6 years ago and it has been fine since).