3mph over the posted speed limit for me. I feel that 58 in a 55 zone is safer than having every impatient idiot on the road passing the slow RV in very unsafe places. People don't seem to use good judgment when passing a slower vehicle and I don't want to be next to the head-on accident they cause. When it says 65 I go 68 to stay with the flow. If your tires, truck, trailer or skill can't safely maintain something close to the speed limit you might think about upgrading. You wouldn't drive a moped with a 35mph top speed on the freeway would ya?