We would always try for a 2.7 mph down speed when targeting Kings. If we were after Lake Trout for a tournament, we would slow to about 2.0 mph. Nothing is cast in stone and different lures run better at different speeds. Even the fish seem to like it different some days. They are a good tool, but if you are tuned to rigger whine, dipsy rod bend, blow back, etc, you will feel when it's right.