Popular for small and compact passenger cars, 185/55 R15 tyres often focus on providing low rolling resistance for better fuel economy. The description contains three numbers and one letter, communicating essential information about the tyre’s dimensions and constructive type.
The first indicator is the number 185, and relates to cross-section width. It tells us that this tyre is 185 millimetres wide from sidewall to sidewall, which is slightly more than the actual width of the tread. Following this, we have the number 55 – the aspect ratio. It means that cross-section height (sidewall height from tread to rim) is 55% of the width.
This description also contains one letter – the ‘R’ stands for radial construction, which is the norm for passenger cars and most other light vehicles. This, in turn, is followed by the number 15 – the inner diameter of the tyre. It lets us know that this tyre is compatible only with 15 inch rims.