Firestone Winterhawk 4 is a winter tyre made in total of 100 sizes, ranging from R14 to R14 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/55 R18 is 80mm wider than the narrowest dimension (155) and 40mm narrower than the widest one (275). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (235mm), which results in 129.25mm sidewall height. In 235/55 R18, there are 2 possible speed indexes for Firestone Winterhawk 4 - "H","V", which are good for speeds up to 210, 240 km/h. In 235/55 R18, Winterhawk 4 usually competes against Blizzak LM-005, which is a tyre from Bridgestone with a rating of 87%, compared to 65% of the Firestone in question. Latest test in 235/55 R18 was held by Autozeitung in 2021, where Winterhawk 4 received rating "Highly recommended" and finished on the 5. place. It was tested on a VW Tiguan.
