Tire Combinations

IMPORTANT: Avoid excessive power train wear. Do not mix worn and new tires, bias and radial, or tires of different diameters. Do not use R2 tires in combination with R1.

Tires are placed into groups by their Rolling Circumference Index (RCI). Rolling circumference is the distance a tire travels in one revolution. Tires within a group, regardless of rim size, are the same or nearly the same height. Knowing and understanding RCI and group sizes makes choosing front and rear tire combinations easier.

RCI is important for proper tractor setup. Since front tires are smaller than rear tires, front tires have to rotate faster to cover the same distance as the rear. Therefore it is important to select the correct size to optimize efficiency and ensure longer tire life.

The front tire must be from a group that is five group sizes smaller than the rear tire group. For example, if the rear tires are group 47, then the front tires must be group 42. The rim size is of no consequence. Different rim size tires such as 18.4R46 and 20.8R42 have the same rolling circumference group, which is 47. Tire sizes are found in the following tables.

If you have any questions or need assistance in choosing the correct combination, see your John Deere™ dealer.

FRONT TIRES
	Minimum Recommended Row Width mm (in.)
	762 (30)	812.8 (32)	1016 (40)+
	Tire Width mm (in.)
Group Size	420 (16.9)	480 (18.4)	520 (20.8)	620 (23.1)
43	420/85R34	480/70R34	540/65R34	600/70R30
42	16.9R30 420/90R30	480/70R30	540/65R30	600/65R28

REAR TIRES
	Minimum Recommended Row Width mm (in.)
	762 (30)	812.8 (32)	1016 (40)+
	Tire Width mm (in.)
Group Size	480 (18.4)	520 (20.8)	620 (24.5)	710 (28)
48	480/80R50	520/85R46	620/70R46 650/85R38	710/70R42
47	480/80R46	20.8R42 520/85R42	620/70R42 650/75R38 650/65R42	710/70R38