The sum of four tires’ maximum load ratings must exceed the maximum loaded vehicle weight (“GVWR”). In addition, sum of the maximum load ratings of two front tires and of two rear tires must exceed each axle’s maximum loaded capacity (“GAWR”). Original equipment tires are designed to fulfill those conditions.
The maximum loaded vehicle weight is referred to Gross Vehicle Weight Rating (GVWR). And each axle’s maximum loaded capacity is referred to Gross Axle Weight Rating (GAWR). The GVWR and each axle’s GAWR are shown on the vehicle certification label affixed to the driver’s door.
The GVWR and front and rear GAWRs are determined by not only the maximum load rating of tires but also loaded capacities of the vehicle’s suspension, axles and other parts of the body.
Therefore, this means that the vehicle cannot necessarily be loaded up to the tire’s maximum load rating on the tire sidewall.
Adverse safety consequences of overloading on handling and stopping and on tires
Steps for Determining Correct Load Limit
Uniform tire quality grading standards
Passenger’s frontal airbag ON and OFF indicators
Models with SRS airbags and lap/shoulder restraints for driver, front passenger,
and window-side rear passengers