Wheel Center Bore vs. Wheel Offset
Comparing 2 standards across 13 specifications. 13 key differences identified.
The Wheel Center Bore (measured in millimeters to 0.1 mm precision) is the machined center opening on the back of a wheel designed to fit snugly over the vehicle's raised wheel hub snout. Ensuring the wheel is mounted 'hub-centrically' (bearing vehicle weight on the center hub collar rather than the lug bolts), preventing high-speed vibrations.
Wheel Offset (denoted as ET from the German 'Einpresstiefe', measured in millimeters) is the distance from the wheel's true centerline to the mounting hub face. Dictating whether wheels tuck inside fenders (Positive ET), sit centered (Zero ET), or poke outwards (Negative ET), offset directly controls suspension scrub radius, steering stability, and brake caliper clearance.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Hub-Centric Engineering Function
|
Center hub collar centers the wheel with zero eccentricity and supports vehicle radial shear loads | — |
|
Volkswagen / Audi (VAG MQB)
|
57.1 mm center bore (VW Golf, Jetta, GTI, Audi A3, TT) | — |
|
Audi / Mercedes-Benz / BMW G-Chassis
|
66.6 mm / 66.56 mm center bore (Audi A4/A6/S4 MLB platform, Mercedes C/E-Class, modern BMW) | — |
|
BMW Classic (E & F Chassis)
|
72.6 mm (standard BMW hub) | BMW E39 5-Series exception: 74.1 mm | — |
|
Subaru / Toyota GT86
|
56.1 mm center bore | — |
|
Honda / Acura / Nissan
|
64.1 mm (Honda/Acura) | 66.1 mm (Nissan/Infiniti) | 60.1 mm (Toyota standard) | — |
|
Hub-Centric Rings (Spigot Rings)
|
Machined aluminum or polycarbonate adapter rings (e.g. 73.1mm aftermarket wheel bore -> 57.1mm VW hub) | — |
|
Definition of Offset (ET)
|
— | Distance in millimeters from the physical geometric centerline of the wheel width to the mounting hub contact face |
|
Positive Offset (+ET, e.g. ET+45)
|
— | Hub face is located toward the outer street-facing side of the wheel (standard on front-wheel drive and modern AWD cars) |
|
Zero Offset (ET0)
|
— | Hub mounting face aligns exactly with the true centerline of the wheel width |
|
Negative Offset (-ET, e.g. ET-12)
|
— | Hub face is recessed toward the back/suspension side, pushing the wheel outwards into a deep-dish stance (lifted 4x4 trucks) |
|
Scrub Radius Impact
|
— | Decreasing positive offset pushes wheels outwards and creates positive scrub radius (increases steering kickback and torque steer) |
|
Brake Caliper Clearance (X-Factor)
|
— | Spoke curvature independent of ET that clears large Brembo multi-piston fixed brake calipers |