Some useful approximations for tyre sizing.

Remember that Radial tyres are on the whole 80% the diameter of the cross ply, so very often a tyre that is the equivalent could be small on diameter, but to get the diameter then it's a much "fatter" tyre, which often doesnt suit. We can always try and advise if you are stuck as to which Blockley radial tyre size you require! For example cars maufacturers that specified 6.40x15 in period would give differing radial options of 165R15 and 185R15. . . . you'll find tyre charts elsewhere saying 5.20x13 is equivalent to a 155R13, which is just not the case, and so on. But all the same the list below should prove helpful, and a useful start. And you can always get in touch letting us know what older car you have, and we can advise.