Headlights.. Daytime

To me, the biggest advantage to DRLs over just turning on your lights (like covering the sensor) is that you aren't constantly running your tail lights. That makes your rear brake lights easier to contrast during the day but still gives you the benefit of being seen from the front. It's probably not enough to be an issue on a tow vehicle, but some trailer lights make it really hard to discern the brake lights from the tail lights in the sun.

Offer void if your tail lights and brake lights are separate. Your mileage may vary.