Technical
information
A guide to the five numbers on every spec sheet
Everything you need to read a wheel fitment — from the certification mark to bolt pattern, centre bore, offset and seat type.
01Quality you can trust
JWL certification
JWL stands for "Japan Light Alloy Wheel" — the official wheel testing standard developed in Japan and now recognized globally as one of the most rigorous benchmarks in the industry.
RS Wheels voluntarily submits every product to JWL testing despite it not being a legal requirement in Canada. This means each wheel undergoes rotary bending fatigue tests, radial fatigue tests, and impact tests before it reaches you.
When you see the JWL mark, it means the wheel has been engineered and verified to withstand the demands of four-season driving on Canadian roads.
- Rotary bendingfatigue
- Radialfatigue
- 13° impactstrike
02Pitch circle diameter
PCD
PCD (Pitch Circle Diameter) is the diameter of the imaginary circle that passes through the centre of all the wheel bolt holes. It determines whether a wheel will physically bolt onto your vehicle.
PCD is expressed as two numbers — the bolt count followed by the circle diameter in millimetres. For example, 5×112 means five bolts arranged on a 112mm circle.
Matching the correct PCD is essential for safe fitment. Using an incorrect PCD can cause vibration, stud damage, and in extreme cases, wheel separation.
5 bolt holes112 mm circle through their centres
03Hub-centric fitment
Centre bore
The center bore is the machined opening on the rear of the wheel that fits over the vehicle's hub. When this bore matches the hub diameter exactly, the wheel is "hub-centric" — meaning the hub carries the weight of the vehicle, not the wheel bolts.
RS Wheels produces model-specific wheels with precise center bore dimensions for each vehicle platform, eliminating the need for centering rings and ensuring a vibration-free ride.
On universal-fitment wheels, centering rings are used to bridge the gap between a larger bore and a smaller hub. Without them, the bolts bear lateral loads they were not designed for.
04Wheel positioning
Offset
Offset is the distance in millimetres between the wheel's centreline and the hub mounting surface. It determines how far the wheel sits in or out of the wheel arch.
A positive offset pushes the mounting face toward the street side of the wheel, tucking the wheel further under the car. This is the most common configuration on modern front-wheel-drive and all-wheel-drive vehicles.
A negative offset moves the mounting face toward the brake side, pushing the wheel outward for a wider, more aggressive stance. Zero offset means the mounting face sits exactly on the centreline.
- PositiveMounting face toward the street side
- ZeroMounting face on the centreline
- NegativeMounting face toward the brake side
05Lug nut contact type
Wheel seat
The wheel seat is the surface on the wheel where the lug nuts make contact. Using the wrong seat type can cause the nut to sit incorrectly, leading to improper clamping force and potential safety issues.
RS Wheels specifies the correct seat type for every model. Always match the lug nut style to the wheel seat type — this information is listed in the specification table on each product page.
Rounded, ball-shaped seat. Common on European makes.
Tapered 60° seat. Standard on most Japanese and domestic vehicles.
Flat washer seat with a straight shank. Common on Toyota trucks and Land Rovers.
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Every product page lists the complete fitment table — PCD, offset, centre bore and seat type for each size.