PTOM - Precision Tire Optimization and Monitoring
Not sure if you are running the right pressure in your tire?
The right pressure will:
- Eliminate road lope and power hop!
- Reduce soil damage!
- Increase crop yields and traction!
- Save fuel!
All without having to change to expensive LSW assemblies!
Proper tire selection and air pressure can make the difference between a high-performing tractor and an underperforming one.
Tires are quite literally where the rubber meets the road for tractor performance.
There are many variables that must be taken into consideration when figuring the right air pressure for your situation and equipment. Our PTOM experts at NTS would be very glad to help you out with this and have the scales and expertise to do this right on your farm! Just give us a call at 1-800-854-4554 and we will schedule you in, weigh up your equipment, record the results, set the pressure and track the overall results for you.
However, for those who are too far away to make this feasible or for those of you that want to do it yourselves right now we are more than glad to share this info right here on our website.
To start with there is the need to understand the difference in tire technology. Do you have bias ply or radial tires? What is the brand and model? If radials, are they standard, IF, or VF radials?
Next, what is the load index or ply rating of the tires? Then you need to take into consideration the soil types and weather conditions.
Then on the equipment side of things, what is your axel weight, front and back? Empty and when loaded or hooked up to the implement being used?
Once you have this information then you can calculate the proper air pressure for each tire. While we would normally take into consideration how different brands and models do actually perform differently in real life, for ease of use we are offering just one sheet to calculate.
Radial Tire Types
Then the difference in Radial tires. Flexion tire technology offers improved performance and cost of operation.
How are increased flexion (IF) and very high flexion (VF) tires different than standard technology radial tires?
- 20 percent less air pressure to carry the same load as a standard radial tire
- 20 percent greater load capacity than standard radial tires inflated to the same pressure
- 40 percent less air pressure to carry the same load as a standard radial tire
- 40 percent greater load capacity than standard radial tires inflated to the same pressure
Load Index Chart and Terminology
Load index (LI) - A uniform method to report the load-carrying capacity of a tire. For example, 157 LI means the tire has a maximum load-carrying capacity of 4125 kg (9100 lb) at the speed specified by the speed symbol when the tire is inflated to its rated inflation pressure. When a tire is used in single application, there would be 8250-kg (18,200-lb) carrying capacity for the axle (4125 kg x 2 tires or 9100 lb x 2 tires). The load-carrying capacity per tire is reduced by 12 percent when the tires are used in dual application, so there would be 14,520-kg (32,030-lb) carrying capacity for the axle (4125 x 0.88 x 4 tires or 9100 x 0.88 x 4 tires). When comparing tires, the higher the load index number, the higher the load capacity.
Example of load index based on tire size:
A 520/85R42 with a 157 LI and an A8 speed symbol has a maximum load of 4125 kg (9100 lb) at the required cold inflation pressure of 159 kPa (23 psi) and maximum speed of 40 km/h (25 mph).
A 480/80R46 with a 158 LI and an A8 speed symbol has a maximum load of 4250 kg (9350 lb) at the required cold inflation pressure of 241 kPa (35 psi) and maximum speed of 40 km/h (25 mph).
Speed Symbol - The top speed a tire is designed to travel. A8 is rated for 40 km/h (25 mph). B is rated for 50 km/h (31 mph). D is rated for 65 km/h (40 mph). The speed symbol designation alone does not determine suitability for use on 50 km/h tractors.
Tire/wheel assemblies for 50-km/h tractors are specified by John Deere to tighter run out (the amount of sideways motion or wobble in a wheel or tire as it rotates) requirements than for non-50-km/h tractors. The low point of the tire radial run out and the high point of the wheel assembly are determined by measurement and marked by the supplier. The low point of the tire is aligned with the high point of the wheel during assembly by the supplier. The purpose of this requirement is to reduce assembly run out in order to provide improved ride quality. This assembly process is referred to as match mounting.
Tread Designation - The tread designation is used to describe the tread and indicate tire usage. Designs offered are all lug- or bar-type tires and are separated into one of three specifications: R1, R1W, or R2.
R1 is a standard tread and is used primarily for general dry-land farming. These tires have the shortest lug height and the narrowest spacing between lugs.
R1W is a wet traction tread for wet, sticky soil conditions. This tread fills the gap between R1 and R2 tires having a deeper lug with wider spacing than R1 tires but shorter and narrower than R2. R1W is defined as having a lug height about 20 percent deeper than an equivalent R1 tire, but this could vary from 15 percent to 35 percent depending on the tire and manufacturer.
R2 is a tread type used typically with cane and rice or other crops grown in wet muck or flooded fields. Tread depth of R2 tires is approximately twice as deep as R1 tires. R2 tires also have the widest spacing between lugs to allow mud to shed easier. The wide-spaced lugs can show extra wear and cause problems with vibration when roading. R2 tires may not pull as well as R1 or R1W tires in drier soil conditions found in most row-crop applications.
Typically, tires with R2 tread should be matched on the front and rear of a tractor while R1 and R1W treads can be mixed or matched on the same tractor to meet requirements or preference.
With this information and an idea of what you are looking for from your tires in your operation you should be able to work out some good results using the provided tire pressure calculator.
There is a few other things we could go into as well and many tests have been done to show how much fuel can be saved in just a few acers, the percentage of yield increase you can expect, slippage rates, etc, etc.
In the long run the point is getting the right pressure and weight distribution on your tractor, sprayer or combine can accumulate into a huge difference in your whole operation and we are here to help you with that.
The NTS PTOM Team