Correction Factors For Other Tire Sizes

To calculate ground speeds for tractors equipped with rear tires other than 16.9-28(R671 mm), R1 tires, multiply the ground speeds shown for the 16.9-28 (R671 mm), R1 tires from above chart with correction factor.

Correction factor is calculated by: Rolling radius of new tire/Rolling radius of tire for which ground speeds are known

Example: Correction factor for 16.9-30 (R695 mm) with respect to 16.9-28 (R671 mm)= 695/671

Example: Ground speed of 16.9- 30 (R695 mm) at B-2, 2100 engine RPM

6.2 km/h)*(695/671)= 6.4 km/h

NOTE: Speed and correction factor information is based on rolling circumference information which vary with tire manufacturer.