What is the difference between the John Deere 6MH 155 and 6M 165?

Here is how the John Deere 6MH 155 and John Deere 6M 165 compare on John Deere's published specifications:

• Horsepower: John Deere 6MH 155 155 hp vs John Deere 6M 165 163 hp
• Pto horsepower: John Deere 6MH 155 120 hp vs John Deere 6M 165 125 hp
• Weight: John Deere 6MH 155 17637 lb. vs John Deere 6M 165 17637 lb.
• Fuel capacity: John Deere 6MH 155 75.3 gal. vs John Deere 6M 165 75.3 gal.
• Wheelbase: John Deere 6MH 155 108.9 in. vs John Deere 6M 165 108.8 in.