wiring question

[JohnnyRPM]

I'm wiring up some off road lights...I've got everything straight with regards to the schematics, relays, etc...

However, I've got 4 55w lights. The wiring kit they came with had 4 individual positive wires running to the two relays. My question is...to minimize the number of wires running from the roof into the cabin, and out the firewall, can I double up on them? Meaning, can I splice each pair of lights into a single, heavier guage positive wire to run to the relays? The lights came with 20 gauge wire...can I splice them on the roof and run a single say 18 or 16 gauge wire per pair of lights? Just want to make sure it's okay before I go ahead and find the unsulation melts off them or something because I've overloaded the wire.

-John