What is the difference between the John Deere S120 and S130?

Here is how the John Deere S120 and John Deere S130 compare on John Deere's published specifications:

• Wheelbase: John Deere S120 48.9 in. vs John Deere S130 48.9 in.
• Cutting width: John Deere S120 42 in. vs John Deere S130 42 in.