It’s the busiest time of the year for Oklahoma farmer Tom Schickedanz. With the first alfalfa cut in the barn and the wheat harvested, Schickedanz takes advantage of a brief lull to maintain his machines — by checking oil, greasing zerts and making sure tires are properly inflated.

“We have a little dead space here to get caught up, but it’ll get busy again in a week with the hay,” he says.

Between haying, spraying, tillage and harvesting, Schickedanz manages more than a dozen machines. He takes tire maintenance seriously.

“We run three big four-by-eight square balers. On the tillage side, we run two four-wheel-drive tractors,” he says. “Air pressure is the key to everything; it just depends on your application.”

Schickedanz estimates he’s able to extend a tire’s lifespan by 25% by making sure it’s properly inflated for each task. The practice also leads to better fuel economy, as well as enhancing yield by not compacting the soil. The savings add up over time.

Fleet management

Before transitioning into full-time farming, Schickedanz, who grew up on a farm, worked for a trucking company. He managed a fleet of about 70 vehicles at an oil field for about a decade.

“We always had tire problems. You had guys who were negligent. They would leave the yard without checking tire pressure,” Schickedanz says. He takes a similar fleet management focus on the farm, where he oversees 12 tractors, three combines, three semitrucks and various implements. 

“Every farmer has a lot of rolling stock when you start thinking about tires: the combines, the tractors, all of the equipment. Farmers have a lot of money tied up in [tires] at the end of the day,” he says. “A lot of older guys who I’ve been around, if they see the tires aired up, they think it’s fine. But he says adding or releasing “just 2 pounds of air in a large tractor tire will make a big difference.”

Calculating weight

While keeping tires properly inflated might be a best practice, calculating the correct pressure for a tractor tire is not a straightforward process. Variables include vehicle weight, implement weight, proper weight distribution and PTO horsepower.

“It is several thousand pounds difference when you go from one activity to another. It’s significant,” says Greg Jones, manager of global field engineering for Firestone Ag.

“When you change what you’re doing, you really need to think about tractor [and tire] setup,” Jones says. “When a tire comes in contact with the soil, you want the maximum amount of footprint. If you’re running 35 [pounds per square inch], you’re probably not going to contact the soil as much as if you dropped the pressure.”

Changing activities without changing pressure can wear down tread, stress mechanical parts and compact the soil. A few weeks ago, for example, Schickedanz’s tractor began “power hopping” when pulling an in-line ripper. His local tire rep came to the farm and calculated the weight and distribution of his setup.

“We calculated the ballast and air pressure for the maximum [tire] footprint. No more hopping. It really made a difference,” Schickedanz says.

How to calculate tire pressure

Minimizing wear and maximizing tire life begins by calculating the optimal tire pressure. Follow these steps:

1. Identify the tractor’s horsepower.

2. Calculate the weight needed for proper setup based on its type:

3. Calculate the recommended front- and rear-axle weight splits based on the tractor type:

4. Weigh the tractor to determine its actual weight.

5. Add or remove weight to the front and back for optimal tractor setup.6. Set inflation pressure using an online tire inflation calculator such as the one at Firestone.