Hi I've been offered cheap winter pirelli tyres for my 20" wheels but they are not quite the same size. The existing tyres are 245 45 r20 but the winters are 255 45 r20. Is is ok to use these - the tyre guy says no problems but I'm not sure?
its actually close to the stock 19 in overall diameter..its fine. If i were you i would go with the 245 with 50 profiles.
No problems you should e fine.
The 245/45/20 has a diameter of 729mm
The 255/45/20has a diameter of 738mm
The stock 235/45/19 has a diameter of 741mm
So as said they are not far away but may make the speedo very slightly out depending on your shoice.
Pete
Thanks guys they are £500 cheaper than the 245 45s so will go for these and err on the side of caution with my speed!