I grew up in the Red River Valley about 20 miles west of the Red River. We easily pulled 5-16s with an R John Deere (45 h.p. drawbar) in third gear which was around 4 1/2 mph. Now I live in the Willamette Valley in Oregon and several of us have or have had a 730 John Deere (54 h.p. drawbar) which have a load at the same speed with 3-16s. Lots of difference where you plow.