Flat Tires Are More Expensive Than You Might Think

Dan Miller
By  Dan Miller , Progressive Farmer Senior Editor
Tethered and overloaded tractors run over a pair of circular tracks paved with various surfaces to simulate extreme wear and tear at Firestone's Ohio test center. Track tests may run 1,600 hours. (DTN/Progressive Farmer photo by Dan Miller)

Downtime because of an equipment tire gone down is expensive. Brad Harris, manager of the field engineering group at Firestone, who also farms in Ohio, said Firestone calculates that downtime during the season's optimal planting window can cost $627 per hour because of the planting delay.

The biggest drag on efficient fieldwork is stubble. Modern corn, cotton and soybean plants are engineered to be strong, to stand up against wind, as well as insect and disease damage. The resulting stubble doubles as an efficient tire killer.

Tires face two hazards from stubble. First is stubble piercing. That's when stubble punctures the tire, causing air loss. Second is stubble erosion. That occurs, as the name implies, over time. The stubble gradually wears through the tire treads to expose the radial cords. The cords contain the pressurized air.


There are ways to fend off stubble damage, Harris said. Drive at an angle to the row, not directly down the row, is one. Another is tread design. Firestone manufactures tires with a "stubble deflector" tread design -- the tread pattern pushes the stubble aside similar to a cowcatcher on a train.

A second tire killer is improper inflation. Inflation pressure must match load. "Guessing is wrong," Harris said. A quality air pressure gauge of $10 to $15 can save many tires. Low pressure, without consideration for load will rapidly damaged the sidewall of a tire.

Air pressure changes by environment -- for example a slippery and muddy field versus a dry road surface with the tires turning at speeds up to 40 miles per hour. High clearance sprayers run on 17-inch tires inflated to 64 pounds per square inch (PSI) to carry 60,000 pounds. Larger planters will transfer 10,000 pounds to the rear of the tractor going from field to road.

"We need to know two things: tire size and the axle load," Harris said. "Then we can use inflation tables or the Firestone Tire Pressure Calculator ( Type in those numbers and you'll get the correct minimum inflation pressure to carry load."

Sometimes the operator will need several inflation calculations for the same piece of equipment because of changes in use and configuration, Harris added. For example, carrying a three-point tillage tool, or running a tractor on duals all year or not. These change air pressure requirements. "In all those cases we need to know how many tires and what those axle loads are," Harris said.


Firestone offers seven ideas for extending the life of agricultural tires.

1. As much as 40% of engine power is lost through rolling resistance and slip. Check tire pressure with a calibrated gauge and set the inflation pressure using a pressure calculator such as Firestone's Tire Pressure Calculator. Harris inscribes the correct inflation pressure in permanent marker near the inflation valve. Correct pressure gives the tire a larger footprint, reduces slip, reduces fuel usage, limits soil compaction, reduces equipment wear and provides a smoother ride.

2. Unlike a human cut, a tire doesn't heal itself. Check the tire sidewalls for cracks, cuts, and other damage. If you see cords, it is time to shop for new tires.

3. Check tire treads and consider replacing if there is less than 20% left. "You'll lose traction in the field," Harris said. "The tries will slip and lose efficiency."

4. A 15-minute check during refueling can prevent costly downtime. Check tire tread areas for stubble damage and exposed cords and replace tires with obvious damage.

5. Check ground contact for gaps between the bar and the ground. If you can put your finger under the bar at the 6 o'clock position on the tire, the tire is likely over inflated.

6. Check valve stems for cracks, corrosion, and debris. Make sure the caps are clean and intact and returned onto the stem.

7. Check nuts, bolts and wheel weights to ensure they are torqued correctly.

Find Firestone's Tire Pressure Calculator at:….Firestone maintains a YouTube channel at:…

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Dan Miller