The High Price of (Under) Inflation

Proper tire inflation is perhaps your greatest daily maintenance responsibility. The relatively short amount of time it takes to check and inflate your tires can save you hours of potential down time, and thousands of dollars in unnecessary wear and wasted mileage (not to mention possible vehicle and payload damage).

And proper inflation can also save your life. The following load and inflation recommendations are provided for use on all Yokohama truck tires used in highway and other heavy-duty operations. The use of these guidelines will result in increased tire tread mileage, fuel economy and casing durability, while improving steering stability and overall vehicle handling.

Included within are current tire load/inflation pressure tables for all Yokohama truck/bus tires. These standards are for Yokohama tires only and should be exclusively used for the recommended tractor/trailer inflation pressure setups as described below:

To correctly determine and set operational inflation pressures for a straight truck (4x2) or a tractor and trailer combination (4x2 or 6x4) in a given fleet, we make the following recommendations:


1. Determine Actual Tire Loads

Weigh several tractor/trailer vehicle combinations that best represent actual maximum load conditions for these vehicles while in operation. Mathematically determine the mean (average) weights per axle of these weighings and divide that value by the number of tires on that axle to determine actual tire loading. While there are different ways to determine tire loading for a given vehicle, actual weighing is preferable, and will provide the best tire load information for setting inflation pressures.

2. Determine Minimum Cold Inflation Pressures For Each Tire Per Axle

Use the actual load per tire (per axle) to determine the cold inflation pressures for the tires by size, ply and type. The actual tire load should be compared to the tire load limits on the chart for the particular tire size and ply rating. The corresponding recommended cold inflation pressure is indicated for the load in the chart heading. In all cases, the tire load limit on the chart should be the same or a larger amount than the actual determined tire load for the ply rating of the tire. If the actual tire loads are heavier than the ply rating of the applied tire, it may be necessary to install a tire with a higher ply rating.

3. Use the determined inflation pressures as minimum inflation values to setup the vehicle for improved handling.

In all cases, the determined inflation pressures based on actual load conditions should be considered minimum pressures. Operational air pressure can be set higher, but in no circumstances should they be set lower.