I use a 4840 to plant with and it has 20.8x38 radials. Tractor data shows the ground speeds in each gear but, the tractor is equipped with 18.4x38. They state in 4th gear the speed is 5.0mph and 5th is 6.6mph. At what rpm was that tested and what would be the difference with taller 20.8x38 tires?
JD 4840 ground speed
