Proper tractor tire maintenance not only helps extend the life of your tires, but also can have significant impact in helping to improve overall efficiency in the field.
According to engineering research, tractive efficiency (getting axle power to the ground) is at best 60 to 80 percent, depending on soil conditions, but proper tire maintenance could improve efficiency by up to 10 percent. That shift in efficiencies can translate into substantial fuel savings, so maintaining your tires does have a positive effect on your bottom line.
Obtaining optimum performance from your tractor tires requires one of your most valuable resources — time. But the time spent checking inflation pressures and adjusting tractor ballast to the application at hand can pay big dividends in terms of improved traction, decreased compaction and overall performance.
Basically there are two factions out in the countryside:
• Those farmers who purchase a radial tire, but don’t like the way they road — to squirmy — so they inflate them to 30 psi, and as a result they have a very expensive bias tire because of the high inflation pressure. This defeats the original purpose in purchasing radial tires — improved traction and flotation.
• The other faction knows the load of the tractor and implement and adjusts the tire inflation pressures to achieve optimum performance. When another implement is attached to the tractor they adjust inflation pressures to account for the new load rating.
“Ultimately farmers should be adjusting inflation pressure with each field activity to maximize the tire footprint, traction, tire wear and overall fuel efficiency,” says Scott Sloan, product engineering manager for Titan Tire Corporation. “It’s all about hitting that load and inflation sweet spot.”
For example, tire inflation during heavy tillage work will be different than when pulling a planter. Why? Because the load varies with each implement, and that load affects the performance of the tire. Let’s say you run a maximum load for heavy tillage at 9,000 pounds and an inflation pressure of 23 psi, but pulling a planter will only load the tires to 6,000 pounds, allowing you to drop the inflation pressure to as low as 6 psi in some cases.
“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,” says Dennis Buckmaster a Purdue University agricultural engineer. “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 (ballast) to add or subtract from the tractor.”
Air pressure is the most critical part of the equation because air, not the tire, carries the load of the tractor and the implement. The best thing farmers can do is to determine, before major field work, the load they will be carrying for various applications (chisel, disk planter, etc.).
“It’s as simple as stopping by a local retailer that has a scale and weighing the tractor and implement,” says Sloan. “Also, if you typically run with additional weights on the tractor, make sure they are in place during this process and that all tanks (fuel and saddle) are full as it’s important to know the true maximum load on the axle. Once you have that information you can determine the desired inflation pressure. If that’s not an option, contact your local equipment dealer and they can provide the weight of the tractor and implement.”
So you’ve calculated the load; how do you determine the optimum inflation pressure?
The Tire and Rim Association of America — made up of all major tractor tire manufacturers — has established a set of recommendations for setting air inflation based on load. These tables can be accessed on the Internet, from tire manufacturer websites or by contacting your local independent tire dealer.
“All tire manufacturers work from the same tables,” says Sloan. “This provides consistency among the tire brands in case you are running two or three different brands of tractor tires across your equipment.”
Not only will adjusting air inflation result in better productivity and fuel efficiency out of your tire, but it can also affect the ride and handling in the field and on the road. Then again there are some compromises. The optimum air inflation for field work may not produce a smooth ride when moving from one field to the next. A farmer can always take time to increase inflation pressure when driving between fields for a better ride and then drop the pressures back down before commencing additional field work. However, not many farmers want to go to that trouble. So instead of running at 6 psi, they will take it up to 12 or 14 psi, which will provide a better ride and still maintain good efficiency in the field.
Air inflation pressure isn’t the only way to get the best performance from your tires and tractor. Ballast is another way to maximize performance in the field by enhancing traction or eliminating an issue, such as power hop. Power hop occurs when the tractor tires load up and let loose, basically causing the tractor to jump in a high-torque application.
To enhance traction additional weight can be added to the front or rear wheels, whereas with power hop you are redistributing weight to the front of the tractor. Ballast should be used to attain enough traction to pass power to the ground without creating excessive wheel slip. Too much ballast can create a deeper track, which can result in power loss because the tractor wheel must climb out of a deeper track.
“There is a wealth of information regarding ballast on the Internet,” says Sloan. “In fact, many tractor manufacturers also have information on how to properly ballast their respective brands.“
When it comes to ballast, case weights are the most popular since they are relatively easy to add and remove from the tractor. Another option is wheel weights that attach directly to the axle of the tractor. The last option is filling the tires with calcium chloride, but this method isn’t used much today.
Before making a decision on ballast, farmers should also take into consideration the type of implement being used. The heavier the implement — chisel — the more traction you get. That does help, but farmers may try to combat that with not ballasting and adjusting inflation pressure. It all goes together — ballasting and inflation pressure — the lower your tire inflation pressure, the less ballast needed, and thus the higher your inflation pressure, the more weight is needed to get the same traction. It’s a balancing act.
Buckmaster adds that the correct weight, tire size and inflation pressure can help reduce slip by half. Or, in other words, 25 percent slip could be reduced to 12 to 13 percent. That’s a significant improvement.
So take some time to care for your tires, and you may be surprised at the results you attain in the field. Your time is valuable, but what better place to invest a couple of hours? The results can lead to better traction, less compaction and improved fuel efficiency. Over the course of a growing season, these small adjustments can help save time and money in the long term.
Goodyear Farm Tires are manufactured by Titan Tire Corporation a subsidiary of Titan International. For more information on Goodyear Farm Tire products and services, visit the company’s website at www.titan-intl.com or e-mail Titan International at firstname.lastname@example.org.