QUOTE(19732.0 @ Jun 28 2016, 02:02 PM)
Can the standard 55/60 watt bulbs really be used without adding relays?
Yes, but anything bigger will need a relay(s).
Might be wrong but for the 90/100w I think you would need 4 SPDT 5-pin relays, 2 (hi-low) for each side. I'd get the 40amp relays and I would also get the matching sockets to make a clean install. You can get these at many FLAPS, off of amazon I think they're about $7ea with sockets. The relay must have five terminals labeled 85, 86, 30, 87, and 87a, these relays are a common bosch copy. If they are not marked with the numbers above they're likely the wrong relay.
Also note that bigger than the 55/60 is actually not DOT legal and I'd never use bigger than the 55/60 in a plastic light housing. I believe the ones in this thread are all glass or glass/metal.