What is the difference between the John Deere 9RX 490 SCRAPER and 9R 540?

Here is how the John Deere 9RX 490 SCRAPER and John Deere 9R 540 compare on John Deere's published specifications:

• Horsepower: John Deere 9RX 490 SCRAPER 483 hp vs John Deere 9R 540 533 hp
• Weight: John Deere 9RX 490 SCRAPER 56714 lb. vs John Deere 9R 540 45122 lb.
• Fuel capacity: John Deere 9RX 490 SCRAPER 350 gal. vs John Deere 9R 540 400 gal.
• Wheelbase: John Deere 9RX 490 SCRAPER 162.5 in. vs John Deere 9R 540 154 in.