BMW Headlight Upgrade

Upgrading your main beam headlights to 100 watts will greatly enhance your night vision. This will increase your safety, particularly when driving at speed. I believe upgrading the main beams is not discourteous to other road users as they should only be used when they won't dazzle other drivers. Upgrading the dipped beams has the potential to dazzle oncoming drivers and is not a good idea.

In the UK dipped beams may legally be 45 watts and main beams 55 watts. Most two headlamp cars can't have the dipped and main beams on together, their maximum output is thus 110 watts. A modified BMW can project 45x2 + 100x2 = 290 watts, quite a difference.

I drive a lot on empty country roads in the winter night and can testify to the difference this modification makes. I don't have fog lamps (they are an option in the UK on smaller engined BMWs) and I believe stronger main beams are more useful for normal driving.

The first task is to upgrade the fuses. The current will be 100W/12V = 8.33A, a 10A fuse should do the trick. On an early E46 you will need to upgrade fuses 29 and 30 (one for each light).

The headlight bulbs are concealed behind sturdy plastic covers which simply clip off from the top. A wire spring holds the bulb in place and one wire connects the 12V supply. The bulb is a "D" type which is keyed by means of one flat face and thus can only be inserted in the correct orientation.

Initially I used a make called Ring for the bulbs. One blew fairly quickly and I am told this isn't uncommon. I went to Hella and they were much better.

This modification will void your warranty and may break the law in your country.

NB: American cars use different headlamp fittings and this mod may well cause damage. This modification should only be performed on european style lights.

If you want an easier job just upgrade to more advanced bulbs from a good supplier but 55W. I used Osram Night Breakers on my E34 325i and they made a massive difference, so much so that I didn't feel the need to go to 100W.