100/80 Watt Bulb vs. 60/55 Watt

By Dennis Santopietro

I have a 2007 Harley Softail Custom and just installed the Harley Billet Headlight. I also installed the Super Spots Xenon 60/55 super white bulb to help improve the normally dim lighting on this bike. I rode in the dark last week and it was scary. I need better lighting so I went on line to different forums and found that several people were running the OSRAM H4 100/80W bulb and were pleased with the results. Many have used this bulb for years. There were,however, a couple of people that said their wiring harness burned up running this bulb. What are your thoughts on using a 100/80 watt bulb in place of the standard 60/55 watt? Do you think the additional wattage will harm my wiring? Thanks – Ron
  The problem is not with the wires that carry voltage to the bulb but with the ground wire. The safest way to run that wattage bulb is to run a 10 gauge wire for your ground all the way back to the battery negative side. Also make sure the connector going to the bulb is tight to the bulb connectors, that way heat does not build up due to resistance in the loose connection. Wrench Safe, Team FMH

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7 Responses to “100/80 Watt Bulb vs. 60/55 Watt”

  1. David Herrera

    Thanks. I have a 1995 Roadking can I upgrade to this same type of light?

  2. Gary Roth

    Some states do not allow them I would check each state for allowing them

  3. Eric

    I also use a pair of “battery hot” relays on the positive side to bypass all the voltage drops! I would do this first, you might be surprised how bright your original bulb can be! The hotter bulb 100/80 also has a shorter lifespan, so keep a spare on hand if you ride a lot. Eric

  4. jerry nordquist

    yeah but how much are they and your total cost was what.........?

  5. Jimmy

    I had the same issue of lighting being very dim on my 02 sportster. I got one of the day maker headlights and have no issue since.

  6. Runswithbeer

    My EXPERIENCE has shown a properly installed relay switch will solve this problem by directing the high voltage directly to the light from the battery

  7. John

    Your best bet is to run led or hid. Both come in plug and play