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What happens when the offset a wheel was designed for changes?

Serhii Maslov Section: Wheel offset (ET) Updated: First published:

The diagram above makes it clear that the one thing offset actually affects is where the wheel’s central axis sits relative to the hub. When offset increases, the wheel “sinks” deeper onto the hub, narrowing the track. Reducing the offset, correspondingly, widens the track and “pushes” the wheel outwards.

The main thing a motorist needs to understand is that in both cases, shifting the wheel’s central axis inevitably shifts the steering axis too, changing the steering geometry the designer intended (which affects both the car’s overall handling and tyre wear on corners), and changes the very moments of force acting on the suspension, along with the directions in which they are applied. Taken together, all of this forces the suspension to work in a way the car maker never intended, so its service life and driving safety (especially in extreme conditions) become, in that case, a lottery with slim odds.

So, even if a wheel with an unintended offset sits on the hub without any trouble, that still does not mean this wheel is fit to use safely. If the offset of a wheel you like is greater than standard (the one the car’s manufacturer specifies), one way out of the situation can be using wheel spacers, though finding spacers that suit you will not be so simple.

P.S. Having read this article, experienced motorists often write on the forums that it is not all that dreadful, and that in practice, if a change in offset does cause premature bearing wear at all, the difference from normal (ordinary) wear is not significant. That is partly true, but it can by no means be applied to every car without exception, especially the newer ones. This is explained in more detail on the page “About the site’s author”. Read the whole article on wheel offset

More on this topic

Can you use wheel spacersUsing wheel spacers this way is more or less justified (with the caveats below), but only on condition that the spacers reduce the wheel’s offset exactly to the standard figure (the one the car maker… Spigot rings for wheels: everything you need to knowOpinions on spigot rings are divided: some say they are unnecessary, others that they are absolutely essential, and of good quality at that. So which is it? How do you choose spigot rings?If a wheel’s centre bore does not match the size of the hub’s spigot, the problem can be solved by fitting special spigot rings, which are sold at tyre centres. Wheel markingsWheel markings. What is stamped on a wheel? The main markings on a wheel usually look something like this: 6.5J x 15 5/112 H2 ET45 d 57.1. Why does a wheel need a centre bore?The centre bore, and the centre bore alone, is what a wheel needs for fitting correctly onto the hub, not the tapered seats on the bolts (or nuts), whatever some sellers may claim. Why are there tapered seats on wheel bolts and nuts?The tapered seat on wheel bolts (or nuts) is not designed to, and cannot, guarantee precise centring of the wheel on the hub.