My OEM wheel measurements are as follows 6J x 15", ET45mm, PCD 4x100, 54.1mm Centre Bore. My new aftermarkets have not deviated in any way other than an increased offset to ET47mm.

Will this widen, OR narrow my wheel track by 4mm?

I vaguely understand the principle of offset and understand there is positive and negative, but I've had a number of different answers and am just looking for a definitive yes/no.

Thanks in advance,


  • In terms of safety, why would you do this BEFORE understanding the consequences, if any?
    – Solar Mike
    Commented Sep 28, 2017 at 9:33
  • I'm thinking there will be a microscopic effect on spring rate. Car will sit a little bit higher with a bit more ground clearance. (I know this because moving the track wider is a way to lower a car. )
    – zipzit
    Commented Sep 28, 2017 at 14:24

1 Answer 1


Going from ET45 to ET47 each wheel will be further tucked in by 2mm so your track will narrow by 4mm.

ET Example

The ET is easiest explained as the offset of the mounting surface from the centre of the wheel (labelled as WHEEL SYMMETRY AXLE in the above image)

(Note that in the image the lower wheel with the larger ET looks like it is offset further out but this due to its 9" width compared to the 6" wheel above)

You could use a 2mm hub spacer on each wheel to return them to the original position.

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