Offset and track myths
Many people are going to change the wheels on their car either for performance or looks. Here’s some reasons:
- fitting of wider tyres (mostly a benefit to roadcars)
- lighter weight (e.g. forged vs cast)
- lower or higher profile; 4x4s typically go higher profile eg 17s over 20s
- cost – OEM wheels are really expensive
- strength (load rating)
Now when you change your wheels you need to consider many things, of which offset and track are two and perhaps the most important. If you try to fit a 5-stud wheel to a 6-stud car it will be pretty clear very quickly that’s not going to work, but the changes in track and offset are more subtle.
So here’s some questions:
- how does changing tyre width affect track? (hint – most people got this wrong when I asked on FB, as they confused track with width)
- what’s the maximum legal track increase in Australia? (hint – it depends on the car)
- how do you calculate track change from looking at offset?
- What’s the difference between ET55 and +55?
- Where do you find offset on a wheel?
All is explained in the video below:
by Colin Lewis
Clear and fact-based as always – good video! I might suggest that when measuring, instead of trying to measure centre to centre of wheels/tyres to get track, measuring the inside of one to the outside of the other gives the same result and may be easier.