If i was to drive under the speed limit everywhere I went, I would never get there alive. people will run you off the road. Also I have seen cops pull over people plenty of times for doing under the speed limit around here for acting suspicious. Keep it 5 over and they will not think twice about it, do 10 over and they might consider (1 in 10 chance) pulling you over. however if you're 15 over you're getting nailed. But it sounds like the CVI was just out to bust nuts and he would have been pulled over anyways.