Last month I attended a National Capital Chapter DIY event held at Scandanavian Import Service Center in Rockville, MD. It was time to replace the differential fluid in my E39 M5, as well as swap out the air filters and the fog light halogen bulbs.
I hadn’t changed the differential fluid since 2013. That sounds like a long time ago, and in most ways it is. But not for differential fluid, for which intervals are based on mileage not time. Even though it was almost 12 years ago, the car had only traveled about 35K miles. That’s at the low range for a suggested change, 30-60K miles. The M5 requires a fluid weight of 75×140 with special friction modifiers, I first put 75×90 in back in 2013 and had to redo the job.
This job is a good example of one made so much simpler by putting the car in the air. Just make sure you undo the fill plug first, since if you drain first and can’t refill then you’re not driving the car. Mine broke free pretty easily since I didn’t overtighten back in 2013. The air filters and fog light bulbs could easily have been done at home but I waited until the DIY since I’d have plenty of time after the fluid change.
When I first bought the M5 I didn’t know all that much about the various kinds of halogen bulbs. The one main thing I wanted to do was to match the headlight and fog light colors. With stock bulbs the fog lights are much more yellow than the HID headlights. I bought a pair of inexpensive bulbs that did that job well.
But there are better performing bulbs out there. The bulbs I replaced them with were Osram Nightbreakers with a high rating. But they were the same exact bulb, interchangeably known as 9006 or HB4. These bulbs are commonly the low-beam headlight bulb on cars with halogen lighting. While catching up on halogen bulb facts I remembered that there is a way to insert 9012, also known as Halogen Infrared Reflective (HIR2) bulbs, for 9006 applications. It’s an advanced design invented by GE in the late 1990s that delivers better performance while using no more power or producing more heat. Here’s a good description from BetterAutomotiveLighting.com.
Today’s HIR (Halogen Infra-Red) incandescent light bulbs produce 75% of the light output of HID headlights at 25% of the cost. They are a single filament bulb with the same base and o-ring style as a 9005 or 9006 headlight bulb. These bulbs attain light levels 75% to 110% brighter than stock as a result of an engineering process by GE that deposits multiple, yet almost invisible, layers of semi-reflective coating on the surface of a specially shaped quartz bulb. This coating reflects a portion of the infrared energy emitted by the filament back onto the filament, causing it to glow brighter and emit more light from the uncoated forward portion of the bulb. Although the filament gets hotter, the glass does not.
I don’t know about twice as powerful, but these bulbs are superior. I’ve read John Deere pushed to have them developed for their tractors since they did not want the expense of upgrading to HID. The only downside is shorter bulb life. As noted above there is also a HIR replacement for the halogen 9005 HB3 bulb, which is a common high-beam bulb in many car models.
All that is needed is to file down one of the plastic prongs on the base of the 9012 bulb, as shown in this video. Was very easy to do with my dremel, and the M5 is now piercing the night with Sylvania SilverStar Ultra 9012s.
Nothing to do with the DIY, but I also purchased a nice-looking trunk mat for my M5. These have been NLA from BMW for years. So a guy named Alex in the Facebook E39 M5 group made some, and I bought one with a European cut to fit the cubby I installed a couple of years ago. It’s fun how the enthusiasm around these cars continues to produce new products and services to keep them at their best.
M3 Front End Refresh Continued
What got me thinking so much about the 9012s was my continued refresh of the M3’s front end. The fog lights were original and showing some wear after almost 20 years so I decided to replace them. I purchased ZKW foglights, an OE provider, for almost half of what BMW-branded foglights cost – $122 vs. $203. The glass lenses are clear, unlike the “fluted” glass that the later E46 M3s came with originally.
I went with Vosla 9012 +120 bulbs, which supposedly are the best you can get. The Lamin-X protective film that I purchased for the new headlight lenses came with covers for the fog lights, so they should remain minty for years to come.
A different route some owners take is putting LED bulbs into assemblies designed for halogen. It’s easy to go wrong doing that, and many of the brightness claims made by LED bulb makers have been disproven in comparison reviews. Massachusetts just passed a law making it illegal to put LED bulbs into a headlight assembly designed for halogen.
I wasn’t interested in exploring, but if you are here’s a good informational video. And another one here.
That’s more information about halogen bulbs than you ever knew you needed. With HID, LED and (someday) laser technology becoming increasingly common for automotive headlights the humble halogen bulb isn’t that sexy. But why not get the best performance you can without the expense and complication of upgrading to HID or LED technology, especially when the modification is so easy? Happy early summer and enjoy the ride.
UPDATE – Bulb related and not worth its own post – I installed LED license plate lights on the M5 for a more modern look in back. As is often the case Ryan at E39Source has a video showing how to do it.
