Tire Difference: Comparing Sprayer vs. Tractor

Editor’s Note: This Q&A originally appeared in AG Tire Talk to provide answers that farm equipment dealers have about farm tire technology. This series features a trending question followed by an abridged version of the answers. For the complete answers, check out www.agtiretalk.com.

Sprayer vs Tractor Tire Difference

What is the difference between a Row Crop Sprayer Tire vs Tractor Tire (Void Ratio / Tread Depth / Tread Design / Standard vs VF / Load Speed Index) and why is it important for producer to match the correct tire for the application?

AG TIRE TALK KEY TAKEAWAYS

•  YOKOHAMA: “Like so many segments in the tire industry, sprayer tires have become very specialized—it’s really the opposite of a one-size-fits-all market…we’ve seen amazing response to the unique hybrid tread pattern—industrial-style tread blocks arrayed in an R- 1-style curved pattern to enhance traction and self-cleaning…”
•  MICHELIN: “Compared to a tractor tire, the stability of a sprayer tire is of utmost importance. Sprayer tires are specifically designed to handle the constant pitch and sway of a machine loaded with liquid, in addition to the dynamic loads, with a very high center of gravity.”
•  TRELLEBORG: “A major difference between a tractor tire and a sprayer tire is tread depth…the term tractor is derived from the Latin word “trahere”, which means “to pull.” Consequently, a tractor tire needs to pull whereas a sprayer tire needs to float on the ground and provide some traction, but flotation and stability are its main contributors.”
•  BKT:  “Standard tires for tractors and tires for sprayers can be the same sizes, which can lead to some confusion…farmers should be careful to make sure that the tires used can carry the weight of the load and are rated for the speed.”
•  CONTINENTAL:  “A high void ratio means there is more gap in the tread than rubber contacting the driving surface…This is a benefit for self-cleaning efforts and soil compaction, common to tractor tires.  A lower void ratio provides good traction, a smoother/more comfortable ride and provides better stability, common to sprayer tires.
•  PRECISION INFLATION: “Which is better, Standard, IF or VF?  If soil compaction, flotation and soil health is important, then IF or VF are the best choice for sprayer and tractor high load requirements.”
•  MAXAM: “In sum, as a general rule the following sets a sprayer tire apart from a tractor tire: lower void ratio, higher weight carrying capacity, shallower tread, and higher speed rating.”

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer
Let’s start this AG Tire Talk with some basic definitions:

A tractor is a vehicle designed to provide a high tractive effort (pulling force) at slow speeds in order to haul a trailer or machinery used in agriculture or construction. The term tractor is derived from the Latin “trahere”, which means “to pull.”

Agriculture sprayers are complete spray systems engineered for generating pressure to drive spray fluid from a tank out to the sprayer’s nozzle(s) to crop or soil.  Sprayers are most often used for the administration of water, insecticides, pesticides, herbicides, and fertilizer.  Sprayer tires need to pass over the soil and crops consequently high traction is not necessarily needed.  High speed is also a necessity. Obviously these two definitions are very different, consequently they will need very different tires.

WORKING SPEED
The need for higher productivity in the world’s agricultural industry drives the professional and extensive use of modern sprayers. New generations of fertilizers and self-propelled high-powered sprayers require a significant upgrade in tire technology to cope with new, high demand applications, through high load, stability, and reduced fuel consumption. Current sprayers and spreaders normal working speed is between 25 and 30 mph.  Transport speeds are up to 45 mph. Sprayer specific tires must at least have a speed symbol of “D” (40 mph).

TREAD DEPTH
Another major difference between a tractor tire and a sprayer tire is tread depth. Sprayer tires normally have an R-1 tread design, where as a tractor tire normally has an R1-W tread design. The main difference is an R1-W lug design is 20% taller than an R-1 and assures a higher traction transfer from the tractor to the ground.  Below details the difference:
The advantages:
Tractor tire is designed with the deeper tread. It will provide more traction and pulling power.
Sprayer tire is designed with the shallower tread. It will provide more stability, less heat build-up and a smoother ride on the road.

TREAD DESIGN
The tread design on the right is that of a sprayer tire and the picture on the left is a tread shot of a high horsepower tractor tire.
Note the difference between the two patterns.  First to note is the pair of lugs in each design, on the sprayer tire we have 29 pairs of lugs vs 23 pairs on the tractor tire. The tread void or lug void is a lot smaller or narrower on the right sprayer tire vs the left tractor tire.  Tread void or lug void is defined as the distance between the lugs and in the case of the sprayer tires its smaller as we have more lugs.  The lugs being closer enables the tread to provide a much smoother ride.  A sprayer tends to spend more time roading than a tractor.  The lugs are wide to guarantee stiffness when the machine is operating under high load when the tank or hopper is full.