Nokian WR D4 is a winter tyre made in total of 82 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/45 R18 is 70mm wider than the narrowest dimension (155) and 50mm narrower than the widest one (275). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (225mm), which results in 101.25mm sidewall height. In 225/45 R18, there is only one possible speed index for Nokian WR D4 - "V", which is good for speeds up to 240 km/h. In 225/45 R18, WR D4 usually competes against Wintercraft Wp52, which is a tyre from Kumho with a rating of 61%, compared to 0% of the Nokian in question. Latest test in 225/45 R18 was held by Sportscars in 2015, where WR D4 received rating "Satisfactory" and finished on the 6. place. It was tested on a .
