PIRELLI 185/70 VR 15
The tyres size 165HR15 was a pretty common tyre size, used by sports cars of the 60's. When low profile tyre technology was develop some car manufacturers (such as Porsche; with their 911), moved onto low profile tyre technology fitting 185/70VR15. The side wall height of a 185/70VR15 is 70% of 185mm tall. the side wall height of a 165R15 is 80% of 165mm tall. These 2 side wall heights being the same made the 185/70VR15 the ideal low profile alternative.
185/70 R 15 CN36 Tires
Porsche jumped on the opportunity to take advantage of, one of the worlds best tyre manufacturers, new developments with low profile tyres, and fitted PIRELLI's 185/70VR15 CN36 CINTURATO ™ tyres to their 911, 924 & 944 cars.
Many people with cars that fit a 165R15 often want to fit a wider tyre, under those circumstances the 185/70VR15 CINTURATO ™ CN36 tyre would be an idea. It is worth considering if you have a car like a TR4, TR5, TR6 or MGC the manufacturers of these cars chose to fit 165R15 tyres long after the 185/70R15 tyre size had been invented. They stuck with 165R15, because that is how these cars handled best, under these circumstances possibly the 165HR15 PIRELLI CINTURATO ™ CA67 tyre would be a better option.