The Kubota M4-061 tractor tire size is front 320/85R20 and rear 420/85R30.
Front tire320/85R20
Rear tire420/85R30
Front/rear setupDifferent front and rear tire sizes
Tire pressure16 PSI, 23 PSI, 22 PSI
Rim diameter20 in front, 30 in rear
Ballast35 gal
Kubota M4-061 Tire Size Details
Front tire size
320/85R20
Rear tire size
420/85R30
Front/rear setup
Different front and rear tire sizes
Front tire construction
Metric radial
Rear tire construction
Metric radial
Front section width
320 mm
Rear section width
420 mm
Front aspect ratio
85%
Rear aspect ratio
85%
Front rim diameter
20 in
Rear rim diameter
30 in
Approx front overall diameter
about 41.4 in
Approx rear overall diameter
about 58.1 in
Tire pressure
16 PSI, 23 PSI, 22 PSI
Loaded rear tire ballast / fluid capacity
35 gal
Tire Size Comparison Chart
Front rim diameter comparison
This model
20 in
Average
18 in
Low
12 in
High
28 in
Rear rim diameter comparison
This model
30 in
Average
28 in
Low
18 in
High
38 in
Benchmarks use typical low, average and high rim diameters for the compact / utility tractor category, not scraped low/high outliers.
Kubota M4-061 Extra Tire Notes
Tire size note
The Kubota M4-061 uses different front and rear tire sizes in this data: front 320/85R20 (20 in rim, 320 mm width) and rear 420/85R30 (30 in rim, 420 mm width)
Pressure note
For the Kubota M4-061 with front 320/85R20 and rear 420/85R30 tires, the pressure values captured in the answer are 16 PSI, 23 PSI, 22 PSI. Tire pressure is load-dependent, so use this as a reference value rather than a universal setting
Ballast note
For the Kubota M4-061 rear 420/85R30 tires, the ballast figure captured in the answer is 35 gal. Liquid ballast capacity can change by tire brand, fill percentage, wheel setup and ballast fluid type
Front/rear matching note
The Kubota M4-061 data shows front 320/85R20 and rear 420/85R30. When changing either size, front/rear rolling circumference and lead/lag need to stay within the correct range
Official information note
Mistakes do happen. Tire sizes can change by year, axle, wheel/rim option, tyre brand, tread type and local market. Please check the tire sidewall, operator manual and official kubotausa.com website for official information.
