Pirelli Winter Sottozero 3 is a winter tyre made in total of 14 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/40 R18 is 10mm wider than the narrowest dimension (225) and 40mm narrower than the widest one (275). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (235mm), which results in 94mm sidewall height. In 235/40 R18, there is only one possible speed index for Pirelli Winter Sottozero 3 - "V", which is good for speeds up to 240 km/h. Latest test in 235/40 R18 was held by AutoMotorSport in 2016, where Winter Sottozero 3 received rating "Recommended" and finished on the 4. place. It was tested on a .