R-1 (R1) – for general farming where conditions are dry and average to ideal
R-1W (R1W) – for farming in marginal soil where moisture content is greater and where a deeper tread is needed. Soil is less then ideal to average. The tread depth of an R-1W tire is at least 20 percent deeper then an R-1 Tire.
R-2 (R2) – for farming extremely wet and difficult conditions. Often called a rice and cane tire. The tread depth of an R-2 tire is at least double that of an R-1 tire.
R-3 (R3) – for farming sandy or volcanic ash soils and where you want to minimize soil disturbance. The tread depth of an R-3 tire is usually half that of an R-1 tire.
R-4 (R4) – for light industrial service and highway department work. The tread depth of an R-4 tire is about 70% that of an R-1 tire.
HF – signifies a high flotation tire, these tires are available in a variety of tread depths including HF1, HF2, HF3 and HF4 which have tread depths comparable to R-3, R-1, R-1W and R-2 tires respectively.
F-1 (F1) – single rib steer tire that is often used in extremely wet conditions. F-1 tires best complement R-2 drive tires.
F-2 (F2) and F-2M (F2M) – multiple rib steer tires. F-2 and F-2M tires best complement R-1 and R-1W drive tires.
F-3 (F3) – industrial multiple rib steer tires. F-3 tires best complement R-4 drive tires
I-1 (I1) – rib tread implement tires used on a variety of farm and agricultural equipment, most often found on anything that is towed.
I-2 (I2) – moderate traction tires with a “button style” tread to provide traction in muddy field conditions.
I-3 (I3) – traction tread tires with a bar type treads that looks like smaller versions of R-1 drive tires. Primarily found on self propelled implements and ground powered equipment.