Page 4 - QCC CAT-2025

FINDING YOUR TIRE SIZE

THE TIRE SIZE CAN ALWAYS BE FOUND ON THE SIDEWALL OF A TIRE.
IT USUALLY LOOKS LIKE THE EXAMPLE SHOWN: P235/70R15

TIRE TYPE: For example “P” for passenger or “LT” for Light Truck.
TIRE WIDTH: The width of the tire in millimeters (mm).
ASPECT RATIO: The sidewall height (from rim to tread), shown as a percentage
of the tire width. In this example, the sidewall height is 70% of the tire width.

TIRE CONSTRUCTION: “R” stands for Radial. This is not as important when
choosing a winter traction device.
RIM DIAMETER: The diameter of the rim in inches (in).

MINIMUM CLEARANCE REQUIREMENTS

PASSENGER AND LIGHT TRUCK

MINIMUM TREAD FACE MINIMUM SIDEWALL
SAE CLASS CLEARANCE (A) CLEARANCE (C)
CLASS “S” 1.46” / 37 MM 0.59” / 15 MM
CLASS “U” 1.97” / 50 MM 0.91” / 23 MM
CLASS “W” 2.5” / 63.5 MM 1.5” / 38.1 MM

The minimum clearance specified must be maintained around spring clips,
spring bolts, fenders, braces, splash pans, fuel lines, brake lines, brake
controls and other mechanical components.
The tire size must be known in order to select a tire chain of correct fit. Traction products not only have to fit the tire, but must
also fit within the space provided around the tires. It is important to check your vehicle owner’s manual. The restricted wheel
clearances in most of today’s vehicles may require the use of SAE Class “S” tire chains.
The different SAE Classes incorporate two different measurements: (A) from the tread face of the tire to the nearest obstruction,
and (C) from the inside sidewall of the tire to the nearest obstruction.

Please refer to your owner’s manual for specific tire chain recommendations for your vehicle.

DEFINITIONS OF SAE CLASSIFICATIONS

S.A.E Classifications refers to the area around the drive tires that is allowed for tire chains and cables. This classification is
created by the Society of Automotive Engineers and almost every vehicle since the mid 90’s has been placed in a
category. It is always recommended the vehicle owner look in their owner’s manual before purchasing a traction product.

Regular (non-reinforced) Regular (non-reinforced) and Those passenger tire
passenger tire chains and lug reinforced passenger tire chains that use light
cables for vehicles with chains for vehicles with regular truck components, as
restricted wheel well (non-restricted) wheel well well as some light truck
clearances. clearances. chains.