When choosing wheel spacers, three key measurements determine whether they’ll fit correctly: PCD, centre bore, and hub size. Get these wrong, and your spacers simply won’t fit — or worse, could cause vibration and safety issues. Here’s how to measure each one accurately.
What Is PCD?
PCD (Pitch Circle Diameter) refers to the diameter of the circle that passes through the centre of all your wheel bolts or studs.
It’s written as the number of bolt holes × the diameter of that circle — for example, 5×112 or 4×100.
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The first number (e.g. 5) is how many bolts or studs your car has.
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The second number (e.g. 112) is the distance in millimetres between them across the circle.
To measure it:
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On 4-stud wheels, measure from the centre of one stud to the centre of the opposite stud.
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On 5-stud wheels, measure from the centre of one stud to the outer edge of the furthest stud, then check against a PCD chart for accuracy.
You can also find your vehicle’s PCD using an online fitment guide or by checking the wheel’s stampings.
What Is Centre Bore?
The centre bore is the large hole in the middle of the wheel that fits over your car’s hub lip. It’s measured in millimetres and ensures the wheel sits centrally.
If the bore of your spacer doesn’t match the hub exactly, the wheel won’t seat correctly — leading to vibration and unsafe alignment.
All Killer Offset, Demon, and Bimecc spacers are machined with vehicle-specific centre bores to match each hub perfectly, guaranteeing a snug, vibration-free fit.
What Is Hub Size?
The hub size (sometimes called the hub diameter) is the size of the raised lip on your car’s hub that the wheel or spacer locates on. This matches the centre bore measurement.
Common examples include:
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VW / Audi Group: 57.1mm or 66.6mm
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BMW: 72.6mm/66.6mm
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Mercedes: 66.6mm
To measure, use a digital caliper across the outer edge of the hub lip for an exact reading.
Why These Measurements Matter
PCD, centre bore, and hub size must all match perfectly for the spacer to seat flush and evenly. A hub centric spacer replicates the factory fit, ensuring the hub supports the wheel’s weight — not the bolts. That’s why every Killer Offset, Demon, and Bimecc spacer at Stanced UK is precision-CNC’d to exact tolerances.
The Bottom Line
Accurate measurements mean perfect fitment. Always confirm your PCD, centre bore, and hub size before ordering spacers. The right fit not only looks better — it’s safer, smoother, and built to last.
✅ Shop vehicle-specific hub centric spacers from Killer Offset, Demon, and Bimecc at Stanced UK – precision-engineered for a perfect fit every time.
