For those with any tyre queries.

87Y is the speed rating and load capacity.

87 is the load capacity, and the Y is the speed symbol.

e.g. W = Higher speed rating in conjunction with load index e.g. 83W, are suitable for speeds in excess of 240km/h up to 270km/h. (Load index is given at 210km/h, load must be reduced 5% for every 10km/h over up to 270km/h).

Speed Rating

H - 210km/h (130mp/h)
V - 240km/h (150mp/h)
W (ZR) - up to 270km/h (168mp/h)
Y (ZR) - 300km/h (186.4mp/h)
Z - over 240km/h (150mp/h)

ZR is the Radial Construction. The ZR will come with all Y rated tyres which means your tyres are capable of 300km/h (186mp/h). If your tyres didn't have the Y rating, then they would only be ZR's alone ... capable of above 240km/h (149mp/h). Not as fast as the ZR Y's. Only the W's and the Y's come together with the ZR's as one package. The ZR W's are only capable of 270km/h (168mp/h), so your tyres are faster then them!

Sidewall Marking Explanation

205 - Width of the tyre in millimetres
50 - Height of the tyre sidewall as a percentage of the width. In this case 50% of 205mm. Also know as the aspect ratio.
R - Radial Construction.
15 - The diameter of the tyre's inner rim in inches
91 - Load Capacity of Tyre. In this case its 615kg
V - Speed Symbol. Indicates the max. speed for the tyre at full load. In this case 149.1mph.
E4 - ECE type approval mark, which demonstrates the tyre has been tested as high quality by the European Regulatory Authorities. All Tyres sold by Black Circles carry this mark.



Originally the speed rating was the letter at the end. the zr is also used as a speed rating. I have included the ratings table below

Speed Symbol "N" For vehicles with a speed capability not exceeding 140 Km/h (88 Mph)
Speed Symbol "P" For vehicles with a speed capability not exceeding 150 Km/h (94 Mph)
Speed Symbol "Q" For vehicles with a speed capability not exceeding 160 Km/h (100 Mph)
Speed Symbol "R" For vehicles with a speed capability not exceeding 170 Km/h (106 Mph)
Speed Symbol "S" For vehicles with a speed capability not exceeding 180 Km/h (113 Mph)
Speed Symbol "T" For vehicles with a speed capability not exceeding 190 Km/h (119 Mph)
Speed Symbol "U" For vehicles with a speed capability not exceeding 200 Km/h (125 Mph)
Speed Symbol "H" For vehicles with a speed capability not exceeding 210 Km/h (130 Mph)
Speed Category "VR" For vehicles having speed capability over 210 Km/h (e.g. 195.50 VR 15)
Speed Category "ZR" For vehicles with a speed capability over 240 Km/h (e.g. 205.40 ZR 17)
Speed Symbol "V" For vehicles with a speed capability not exceeding 240 Km/h (e.g. 225.55 R 15 91V)
Speed Symbol "W" For vehicles having speed capability not exceeding 270 Km/h (e.g. 225.60 R 15 96W)
Speed Symbol "Y" For vehicles having speed capability not exceeding 300 Km/h (e.g. 275.40 R 18 94Y)
ZR+ Speed Symbol "W" Tyres marked with both designations for vehicles with speed capability over 240 Km/h but not exceeding 270 Km/h
ZR+ Speed Symbol "Y" Tyres marked with both designations for vehicles with speed capability over 240 Km/h but not exceeding 300 Km/h


The following links are useful

speed ratings http://www.tyresave.co.uk/tyrspeed.html

wheel size calculator. very useful for calculating what size tyres for your bigger rims http://www.tyresave.co.uk/tyresize.html


wheel fittment guide. offsets and pcd for different manufacturers http://www.tyresave.co.uk/fitment.html