Choosing the right tire size and type ensures your tractor performs properly in typical working conditions. Learn to read tractor tire markings to find the right tires for your tractor.
You can find the exact tire specifications in your tractor's manual. Your Nokian Tyres dealer can also help you choose the right tires.
How to read tractor tire sizes?
The tire’s sidewall markings are a combination of numbers and letters that tell you the tire's size and other important characteristics. You can find the following information in these markings:
- Tire’s width. This can be in metric or inch sizes. Check the correct measurements from the size equivalency table below.
- Aspect ratio. A tire's aspect ratio is the ratio of its sidewall height to its width, expressed as a percentage. Common aspect ratios for tractor tires include 85, 80, 75, 70, 65, and 60. For example, in a 70-series tractor tire, the sidewall height is 70% of the tire's width.
- Construction. The letter R stands for radial construction, the hyphen marks diagonal tires, and the letter B is for bias belted tires.
- Rim diameter. The third number tells you the rim diameter in inches.
- Tread classification. The tread classification indicates tire type and helps you choose the right kind of tire for the job.
- Load index. The load index indicates the maximum weight a tire can carry at its maximum speed and inflation pressure. You should never exceed a tire’s load capacity. Check the Nokian Tyres technical manual for a load capacity table indicating the maximum load at different speeds and inflation pressures.
- Speed index. The speed index specifies the maximum speed you can drive with. If a tractor tire has two speed indices (dual speed index), the higher index indicates the maximum recommended speed.
Check the right tire ratio
Account for the tractor drivetrain when buying tractor tires. The tractor drivetrain defines how to choose your front and rear tires. For tractors with mechanical front-wheel drive (MFWD or FWD), it’s crucial to keep the correct ratio of rolling circumference between the rear and front tires. For articulated four-wheel drive tractors (4WD), both front and rear tires should have the same diameter.
Tractor tire size chart
Our technical manual presents available sizes and a tractor tire size chart for each product in our range. The chart provides all the information needed to select the proper tire, including the size marking, wheel width and diameter, rolling circumference, tread code, and load capacity.
With our tractor tire conversion chart, you can easily check the equivalent inch size for metric sizes.
If you are unsure what tractor tire size to choose, our dealers are happy to assist you. Find your nearest Nokian Tyres dealer and get high-quality tractor tires that perfectly fit your needs.
Please remember that it is the driver’s responsibility to ensure their tires are safe and suitable for their vehicle and to follow the vehicle’s manufacturer´s guidelines for proper use and maintenance. Consult your closest Nokian Tyres dealer or your vehicle’s manufacturer for specific advice.
