What is the difference between the John Deere 9R 490 and 9RT 490?

Here is how the John Deere 9R 490 and John Deere 9RT 490 compare on John Deere's published specifications:

• Horsepower: John Deere 9R 490 483 hp vs John Deere 9RT 490 483 hp
• Pto horsepower: John Deere 9R 490 335 hp vs John Deere 9RT 490 335 hp
• Weight: John Deere 9R 490 40660 lb. vs John Deere 9RT 490 47326 lb.
• Fuel capacity: John Deere 9R 490 400 gal. vs John Deere 9RT 490 350 gal.
• Wheelbase: John Deere 9R 490 154 in. vs John Deere 9RT 490 116 in.