Brian

Yes, if both were on the same circuit. But they're not. There's a different circuit for each high beam - and hence a distinct 8A fuse for each. At least according to my shop manual CD.

Kevin

OK, I had not even bothered to look.

So, one 100W bulb will draw 8.3 amps at 12V.

The fuse will likely survive this. Remember, unless you have a dead short, the fuse will take quite awhile to melt at the rated load. It might take just about forever to melt at 8.3 amps.

Additionally, the draw will probably be closer to 7.4 amps with a properly functioning alternator.

Remember, wire becomes more restrictive as it ages. Even if you use only the stock wattage, you can get an upgrade in light performance by using relays and larger wiring. If you have a 15% drop in voltage, you loose about 47% of light (according to Hella).

I use relays on my 2002 Golf and I noticed an improvement in headlamp performance.

I believe you meant resistive, not restrictive. Wire should not get more resistive as it ages, if it does, then it has become corroded or something.
Insulation does get more brittle after a long time especially in high heat areas. Its true that a 3% drop in voltage will give a large (15% or so) drop in light output. Relays help prevent drop, use them when upgrading that is the general practice.

I'd recommend the 55/100w lights over what you have. Wiring a relay in for the high beams is pretty simple. Run a heavy hot wire from the battery (with a fusible link installed for safety) to the Relay supply terminal, with the other side of the relay switched terminal going to the high beams. Run the ground terminal of the relay to a good ground (could even ground it where you mount the relay), and use the original high beam wire to trigger the relay.

First off...go here and view...very easy...

http://brandon.importtransmissionexchange.com/benz_files/lights.htm

Secondly...
55/100w bulbs (off of a 12.5v battery) pull 6 amps on low and 8 on high. I measured it with a Amp meter before I installed them in the car.

I would not recommend using stock wiring as anyone with a w126 knows, when you hit the heater switch your headlights dim and all sorts of power dropping issues.
Its not a matter of excessive amperage per-say but more a matter of voltage drop by the time you get to the end of the wire at the bulb. Light output drops significantly as V drops away at a small rate.

The upgrade to 55/100 is amazing and in the time I have been running them, only had one person high-beam flash me (there was a hill).
My friends say its acceptable light output in their eyes when I am behind them. The cutoff on the Euro H4's helps this a lot...just make sure you take GREAT care and aim them CORRECTLY..

Brandon :)

If you run a high beam at the fuse rating for any length of time, it will age very quickly. Standard engineering procedure is to fuse the circuit with 50% margin. A 100W high beam will draw 7 amps, I would not run it with less than a 10A fuse. Make sure your wiring can withstand it.

What brand of bulbs are you running?
 

Puma has got the Hella H4 bulbs in a 55/60 wattage that draw about 10amps in the Xenon Premium bulb.

They also have the Narva german made bulb in a 55/100 watt but it would pull 200 watts on the switch and 17 amps at high beam.
I guess these you could get away with since you don't run the high beams much - especially if you added a fuesed relay.

I looked at the Sylvania silverstar H4 bulbs and they are more expensive than the Hella or Narva. One of the guys on the forum put in the silverstar bulbs in his Euros and likes them.

Which brand? I'm going to stick with 55/60 watt

Brands of bulbs is like brands of oil filters.

I use the Hella's for no good reason other than the fact that the vendor also sold me the Hella replacement headlights.

I have come to find out, from him, that Hella does not make their own H4 lamps.................. just puts their name on another manufacturer's bulb.

Back to the oil filter BS all over again...................

yeap yeap. I like Narva bulbs, but they are hard to find in the US. Dan Stern carries them.

I use 80W/100W H4 bulbs in Hella 7" conversion lamps. They are running off of an upgraded wiring harness and relay assembly. I have never been flashed because the lights are bothering oncoming traffic. The sharp beam cutoff and proper aiming prevent any problems. The only time I have seen problems with "blue bulbs" or high wattage bulbs is in stock headlights without a sharp cutoff. I do hate Honda and Nissan headlights. Those are blinding.