Powerful John Deere John Deere-designed and -built 6068, 6090, and 6125 turbocharged, air-to-air aftercooled, diesel engines are used in the STS combines.
engines

• 6068 (6.8) liter PowerTech Plus^TM rated horsepower for the 9560 STS is 265
• 6090 (9.0) liter PowerTech Plus rated horsepower for the 9660 STS is 305
• 6090 (9.0) liter PowerTech Plus rated horsepower for the 9760 STS is 340
• 6125 (12.5) liter PowerTech^TM  rated horsepower for the 9860 STS is 375