Plus sizing or up-stepping is the practice of replacing the wheel with a larger one and mounting a lower profile tyre while maintaining the same (or approximately the same) diameter and circumference as the original tyre.

Plus Sizing - Original Size, Plus One, Plus Two

Pros of Plus Sizing

  • Aesthetics. Putting on larger wheels and lower tyres looks really cool.
  • Better handling and cornering due to a wider thread and stiffer sidewall.
  • Greater contact area. Plus sizing usually means putting wider tyres, thus the increase in contact area.

Wheel on the sports car

Tyre size designations can be found on the tyre's sidewall and usually look similar to these:

European Metric Tyre Size Designation

(Valid in Europe, standard ETRTO – European Tyre and Rim Technical Organisation)

European Metric Tyre Size Designation