Correct Load Speed Index & Inflation

Correct-Load-Speed-Index-and-Inflation
Date: 27.06.24
Choosing the right agricultural tire tread design can significantly impact your farm's productivity and efficiency. In this post, we explore the benefits of various tread patterns and help you determine the best option for your specific needs.

All Modern Agricultural Tires have a specific Load Index (LI) and Speed Rating, together called a LOAD SPEED INDEX.


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Stamped on Tire Sidewall, The LOAD INDEX represents Maximum Load Capacity at Maximum Inflation Pressure.
SPEED RATING represents Maximum Speed tires can travel.

So how do you know Maximum Load and Maximum Speed your tires are rated for? Use the International Load Speed Index Chart!


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Using Load Speed Index Chart supplied in the Mitas AG Tire Databook, as you can see above, this tire can carry a Maximum Load of 6,800 lbs. (3,075 kgs.) at a Speed of 25 mph (40 kph).

Want to make sure you have the CORRECT INFLATION PRESSURE for the application? Use the Load Speed Table in the Mitas AG Tire Databook!


Step 1: Determine Tire Size & Load Speed Index.

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As shown above, we have a Mitas AC85 460/85R34 (Size), 147 (Load Index), A8/B (Dual Stamped Speed Rating)


Step 2: Determine your Maximum Axle Load, then look up on Load Speed Table, determining Correct Air Pressure.

If we have a 12,000 lbs. Axle Load, with Standard Two Tire Set Up, we simply divide 12,000 by 2, coming up with 6,000 lbs.

  • We look up 6,000 lbs. on the Table, determining we will need 29 PSI to carry the Load at Speeds up to 30 mph.

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Got a Central Tire Inflation System and want to find Air Pressure at Slower Speed? Take the Load Speed Table a step further! If Axle Load remains the same (12,000 lbs.) and we slow to 6 mph Field Speed, required Air Pressure is 15 PSI:


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Lastly, but most importantly, do not make any changes to tires sizes, air pressures, or set up without confirming all is OK with your
local Certified AG Tire Dealer and Mitas, using only Certified AG Tire Dealers to mount tires.