255/40-R17 tires are 0.31 inches (8 mm) larger in diameter than 245/40-R17 tires and the speedometer difference is 1.2%. 235/55-R17 tires are 1.5 inches (38 mm) larger in diameter than 245/45-R17 tires and the speedometer difference is 5.5%. 245/45-R17 tires are 0.18 inches (4.5 mm) smaller in diameter than 225/50-R17 tires and the speedometer difference is 0.7%. 205/45-R17 tires are 0.81 inches (20.5 mm) larger in diameter than 205/40-R17 tires and the speedometer difference is 3.3%. 245/45-R20 tires are 0.17 inches (4.2 mm) larger in diameter than 225/65-R17 tires and the speedometer difference is 0.6%. 225/65-R17 tires are 0.51 inches (13 mm) smaller in diameter than 235/65-R17 tires and the speedometer difference is 1.8%. Tire 1 / R 225 55 R 17 Tire 2 / R 245 40 R 19 Inch Mill KPH MPH Odometer Reading If you replace 320/60/18 with 235/60/18 for Odometer reading 1000 the actual distance traveled = 879 ~ ( -12.1 %) (If your Odometer is accurate for original tires) Edit and Copy Tire diagram above to compare or print. Speedo Difference between Wheels 12.1% 245/45-R17 tires are 3.86 inches (98 mm) smaller in diameter than 245/65-R17 tires and the speedometer difference is 13.1%. 235/40-R17 tires are 0.57 inches (14.5 mm) smaller in diameter than 225/45-R17 tires and the speedometer difference is 2.3%. 245/45-R17 tires are 0.22 inches (5.5 mm) larger in diameter than 215/50-R17 tires and the speedometer difference is 0.8%. sd5IH5.