About to order a set of four this week. Gotta go with the black though, I'm not cool enough for the flashy red.
Here's what I dug up on mud flap laws in Oregon
FENDERS
6) Does my vehicle need mud flaps/mud guards?
Answer: Non commercial vehicles (under 8,000 lbs.) need fenders or mud guards (mud flaps) within 27 inches of the pavement behind the tire. Commercial vehicles need fenders or mudguards (mud flaps) within 10 inches behind all wheels. (ORS 815.180)
Fenders and mud guards (mud flaps) must cover the entire tread width of the tire(s). (ORS 815.180)
7) How far can a vehicle sit off the ground before mud flaps are required?
Answer: For a vehicle that is less than 8,000 lbs the law states: "...fenders or mudguards must extend in full width from a point on the wheels that is above and forward of the center of the tire over a point at the rear of the wheel that is not more than 27 inches above the surface of the highway." ORS 815-180 (2) (c) The issue is not how far the truck can sit off the ground so much as making sure that fenders or mud flaps are in place not more than 27 inches from the surface of the highway.
More than one person has called me out for not having mud flaps since moving to Oregon. Thats a ticket I'd be ashamed of, especially considering a set of four is probably about the cost of the ticket.