“Flat tires can cause a lot of downtime, so it’s important to do plenty of walk-arounds to check for wear and cracking both on tractors and implements,” said Dennis Buckmaster, Purdue agricultural engineer. “Properly maintaining tires improves equipment efficiency and can mean less labor, fuel and tire wear.”

One way to ensure higher efficiency is to keep tires properly inflated, Buckmaster said.

“A common mistake is that farmers see the inflation pressure on the sidewall and think that is the proper tire inflation, but that’s actually not the case,” Buckmaster said.

“Proper inflation is a function of the load on the tire. There are manuals and tables available on the Internet to help farmers calculate the best possible inflation based on tractor weight, what’s being pulled and the speed traveled. They also can help determine the amount of weight to add or subtract from the tractor.”

If farmers closely inspect tires and find that it may be time for replacements, Buckmaster said there are several factors to keep in mind, including price, warranty, performance and dimensions.

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“The most important thing is that tires be rated to carry the load,” he said. “That doesn’t mean farmers should necessarily replace the current tire with a new one of the same dimensions. Most equipment has several compatible tires, so the original dimensions may not be optimal for certain operations.

“Even with new equipment, the stock tires may not be optimal for a particular operation. In that case, farmers often can trade the new ones for a set that will have better performance.”

Buckmaster also said that correct weight, tire size and inflation pressure can reduce slip by half. Or, in other words, 25 percent slip could be reduced to 12 to 13 percent.

“Tractor power efficiency hovers around 60 to 80 percent, on average, but proper tire maintenance could improve efficiency by up to 10 percentage units,” he said. “That big of a shift in efficiencies translates into fuel savings, so doing it correctly does pay off.”

In addition to improved efficiencies, proper inflation can prevent premature tire failure.

“Underinflated tires run the risk of slipping off the rims, or other failures,” Buckmaster said.

While overinflated tires also have increased risk of premature failure, they cause more field compaction as well.

“Overinflated tires have a smaller footprint, which means less weight distribution and more soil compaction,” Buckmaster said. “For example, maybe the tire wall says to inflate to 25, but the tire may only need 14 to 15 PSI.”

Buckmaster also stressed that the decades-old debate between radial or bias tires is no longer an issue.

“For vehicles primarily used for road travel as transport or utility vehicles, bias might be a suitable tire, but for any tractive functions, radials are the way to go,” he said.  FG

References omitted due to space but are available upon request.

—Excerpts from Ohio State University and Purdue University Ag Answers, January 2010

PHOTO
Even with new equipment, the stock tires may not be optimal for a particular operation. In that case, farmers often can trade the new ones for a set that will have better performance. Photo by FG staff.