What is the fuel capacity difference between the John Deere 6M 155 and 6R 155?

The John Deere 6M 155 has a fuel capacity of 75.3 gal. and the John Deere 6R 155 has a fuel capacity of 74 gal., a difference of 1.3 gal. The John Deere 6M 155 has the higher fuel capacity.