measuring offset?

[eko]

Can anyone tell me if its possible to work out the offset of the wheels in this link;
http://www.e30zone.co.uk/modules.php?na ... ic&t=25389
no marking on any stating the ET number.

[jph78]

It's easy to get an approximatel measurement, and even easier to get an exact measurement with the tyre removed.

For a rough check with the tyre still on the rim......

Lay the wheel face down on a flat surface, this will only work if it's resting on the tyre sidewall, not the actual wheel face.

Lay a straight edge across the upper face of the tyre and measure down to the floor, say for example you get 235mm, note this down.

Next measure down from the same straight edge to the mounting face inside the wheel (the face that sits against the cars hub) for example 145mm and note this down.

Now halve the first measurement (the width) and then subtract the second measurement (the backspace)

(235/2) - 145 = 117.5 - 145 = -27.5

Therefore the wheel would be ET27.5.

This should be accurate to about +/- 2mm

Regards,

Jon.

Before anyone asks, most modern cars use negative offset wheels, but the term ET negates the need for the minus sign.

[eko]

ill try that tomorrow,thanks mate