Wheel Offset Diagram. If the mounting surface sticks out farther than the centerline the offset is positive high offset. You can see how a positive offset will tuck the assembly further under the fender while a zero or negative offset pushes the wheel out towards or even past the fender.
The wheel offset determines where your wheels sit in relation to the wheel arch and is measured in millimeters sometimes quoted as et for example et 45. As in the diagram below the mounting face can be behind red line in front of green line or exactly in line with the centre. Negative offset wheels.
Measure the backspace a and then subtract a from x2.
In other words the mounting surface is where the lug holes are. Wheel fitment for any car your search history news about professional tire tests all in one app. The wheel offset can be positive negative or zero depending on how the tyre sits in the wheel. There are three different offset ranges.