Tyre sizes

[Nats Whiskas]

Hi people

Im looking at replacing the tyres cos they worn, Ive been offered a pair of 205/40/ZR17's at a good price but am wondering what difference it will make with the driving of the car?IIRC the tyres are normally 205/45/ZR17?

Cheers

[stamford]

With that spec you'll be getting -3.25% difference in rolling circumference which means the speedometer will be out, the recommended figure is +/-2.5%. If it were 215/40 then you'd be okay.