Uniform Tire Quality Gradings - Volvo 2008 C30 Owner's Manual

Steps for Determining Correct Load Limit
(1) Locate the statement ''the combined weight of occupants and cargo should never exceed XXX pounds'' on your
vehicle's placard.
(2) Determine the combined weight of the driver and passengers that will be riding in your vehicle.
(3) Subtract the combined weight of the driver and passengers from XXX kilograms or XXX pounds.
(4) The resulting figure equals the available amount of cargo and luggage load capacity. For example, if the ''XXX''
amount equals 1400 lbs. and there will be five 150 lb. passengers in your vehicle, the amount of available cargo and
luggage load capacity is 650 lbs. (1400-750 (5 x 150) = 650 lbs.)
(5) Determine the combined weight of luggage and cargo being loaded on the vehicle. That weight may not safely
exceed the available cargo and luggage load capacity calculated in Step 4.
(6) If your vehicle will be towing a trailer, load from your trailer will be transferred to your vehicle. Consult this
manual to determine how this reduces the available cargo and luggage load capacity of your vehicle.
WARNING
Exceeding the permissible axle weight, gross vehicle weight, or any other weight rating limits can cause tire
overheating resulting in permanent deformation or catastrophic failure.
Do not use replacement tires with lower load carrying capacities than the tires that were original equipment on the
vehicle because this will lower the vehicle's GVW rating. Replacement tires with a higher limit than the originals do
not increase the vehicle's GVW rating limitations.
176
07 Wheels and tires

Uniform tire quality gradings

Uniform tire quality gradings
ALL PASSENGER VEHICLE TIRES MUST CONFORM TO FEDERAL SAFETY REQUIREMENTS IN
ADDITION TO THESE GRADES
Quality grades can be found, where applicable, on the tire sidewall between the tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
TREADWEAR
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions
on a specified government test course. For example, a tire graded 150 would wear one and one half (1 1/2) times as
well on the government course as a tire graded 100. The relative performance of tires depends upon the actual
conditions of their use, however, and many depart significantly from the norm due to variation in driving habits,
maintenance practices and differences in road characteristics and climate.
TRACTION
The traction grades, from highest to lowest, are AA, A, B, and C, as measured under controlled conditions on specified
government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance. The traction
grade assigned to this tire is based on braking (straight-ahead) traction tests and is not a measure of cornering (turning)
traction.