Technical Information

Centering a wheel

Improperly centered wheel will cause vibration when driving. It is important that the wheel be correctly centered on the vehicle's hub. There are two ways to center a wheel on the car. More than 90% of cars actually use wheel nuts to achieve it. This is the reason they are conical or ball seated.

The other way is to use the hub and the studs. In this case, the wheel nuts are flat and the center bore of the wheel matches the hub bore of the vehicle. It is more commonly used on heavy trucks and trailers. Hub centric wheels help the installation by centering studs with the holes on the wheel. It is easier to align the wheel nut into their matched nut seat on the wheel and will help reducing vibration caused by an improper installation.

Offset

It’s the distance between the middle of the wheel and the mounting plate, in millimeter. If you take a wheel with a higher offset than OEM, the wheel is going to get more inside the fender. If the offset is lower, the wheel is going to go to the outside of the fender.

To calculate the offset, you need two numbers: The total width in millimeter divided by two (dotted line) and the distance between the exterior lip of the wheel and the mounting plate (blue arrow). The difference between these numbers gives the offset.

Example: A 200mm width wheel, and 80mm of distance between the exterior lip and the mounting plate. 200/2 = 100mm. 100-80 = 20mm. Wheel’s offset is 20mm.

TPMS

The Tire Pressure Monitoring System is mandatory in the United-States since 2007.

The system aims to alert the driver when a tire is deflated. There is a system which uses the anti-lock brake crowns (ABS) but most automakers uses sensors that check the exact pressure in each tire.

Manufacturers are free to choose the standard to light the lamp in the dashboard. For some, it is necessary that a tire falls below a certain pressure, for others a tire must have some difference with the recommended pressure and finally for some it is simply necessary that a tire is softer than the others.

In all cases it is important to check your tire pressure if the lamp lights. A simple change in temperature (between seasons for example) affects little pressure and turn on the make.

Specifications

• Diameter : It's the diameter of the wheel.
  
  
• Width : It's the width of the wheel. Measured on the inside of the lips.
  
  
• Bolt pattern : It's the configuration of the mounting holes. It indicates the number of hole and the diameter of the circle on which they are positionned.
  
  
• Center bore : It's the diameter of the center hole.
  
  
• Offset : It's the distance between the mounting surface and the middle of the wheel.
  
  
• Backspacing : It's the distance between the mounting surface and the inside lip of the wheel.