Issue link: http://read.dmtmag.com/i/34501
weight for the axle must be used. The maximum axle weight is determined by taking the highest wheel end value and multiplying by 2 for single applications and 4 for dual applications. If the maximum load-carrying capacity of the tire is below the actual scale weight, then tires with greater carrying capacity should be used. This means either a tire with a higher load range or ply rating, or a larger tire size. If the maximum load can be carried by the minimum pressure (as listed on the Load Inflation Chart), then a smaller size tire or a lower ply rated tire should be considered depending on the application and operation of the vehicle. Never reduce air pressure below minimum data book specification without consulting Michelin ® . Ambient temperature will affect the air pressure within the tire. For every 10-degree temperature change, pressure readings will change between 1 and 2 pounds per square inch (psi). Consider this when checking pressures. Check all tires when cold at least 3 hours after the vehicle has stopped. Never bleed air from hot tires. Additionally, altitude can have a slight affect on air pressure. For every 1,000 foot increase in altitude above sea level, air pressure will increase approximately 1⁄2 psi. For example, a tire inflated to 100 psi at sea level will read slightly over 102 psi in Denver, Colorado. Please consult with Michelin ® for additional information on cold and hot climate corrections. RIMS AND WHEELS The correct rims and wheels for each tire size are indicated in the specification tables. For complete tire specifications, refer to application specific data books. MAXIMUM SPEED RESTRICTIONS* Truck tires should normally be inflated according to the specification tables. The carrying capacities and inflation pressures specified in these tables are determined with the tire’s rated maximum speed in consideration. (See specification tables for each tire’s rated speed in the current MICHELIN Truck Tire Data Book.) This is a maximum continuous speed, not an absolute upper limit. Reducing the maximum speed at which the tire will operate and adjusting inflation pressures according to the information contained in the following chart can help increase the carrying capacity. To use the Low Speed and Static Coefficient Chart (Page 10) you must know the tire size (standard conventional size example - 11R22.5 or low profile 275/80R22.5) and the maximum speed rating of that tire. Speed ratings can be found in the data book. Based on the size and speed rating, select the The Tire and Rim Association, Inc. (TRA) permits operating a 65 mph rated tire at higher speeds with a reduced load and increased inflation. No such permission is granted by TRA for tires with speed ratings below 65 mph. * Exceeding the legal speed limit is neither recommended nor endorsed. Section One: Tire Selection 9 correct quadrant (Table A or B), find the speed value desired, and multiply the tire load capacity by the coefficient provided. Also, add the listed increase in air pressure (if any) to the air pressure value for the selected tire shown in the data book. Give special attention to the rim/wheel and vehicle axle ratings that may be exceeded by the increases in load and pressure. Tires optimized for highway applications have a maximum speed of 75 mph. For speeds less than 20 mph (32 kph), please consult Michelin North America, Inc. These limits apply only to Light Truck and Truck tires, but do not include Special Application tires, tires for high cube vans, low bed trailers, urban, on/off-road use and 315/80R22.5 LRL mounted on 8.25x22.5" wheels on steer axles. The tires with “Y” or “L” (see Page 2) as the third character in the tread designations are designed and optimized for on/off-road applications and are speed restricted. These tires should not be used in applications that operate the tires continuously on highways over an extended period of time or at speeds that exceed the speed rating of the tire. This could lead to heat build up and cause premature or sudden tire failure as shown in this photo. Tires with the “Y” designation are for applications expected to be 80% on-road use and 20% off-road use. They have a maximum speed of 65 mph. Tires with the “L” designation are for applications expected to be 20% on-road use and 80% off-road use. Some of the “L” designated tires have a maximum speed of 50 mph while others have maximum speeds of 55, 60, and 70 mph. There is no speed restriction once the casing has been retreaded per the RMA (Rubber Manufacturers Association) and the TMC (Technology & Maintenance Council).