What is the difference between the John Deere F8 300 and F8 400?

Here is how the John Deere F8 300 and John Deere F8 400 compare on John Deere's published specifications:

• Horsepower: John Deere F8 300 498 hp vs John Deere F8 400 537 hp
• Weight: John Deere F8 300 36375 lb. vs John Deere F8 400 36375 lb.
• Fuel capacity: John Deere F8 300 290 gal. vs John Deere F8 400 290 gal.