hi, i have just bought a 2004 tdci focus, it was fitted with 195/60/15 tyres, which were bald on the front.i fitted my fiesta 175/65/14 alloys to get me home from york ( approx 70 miles ) i like the new alloys. question is, how much will this affect the speedo ? if at all. thanks guys. steve.

 

5.19% slow, so your speedo will say 60mph and you'll actually be doing around 54mph at a guess including fords tolerance

 

Reading 60 when its actually 57;

http://www.autopartuk.com/tyre-calculator/

 

hi, focusv8. ive looked on the link you sent me. thank you for your reply. cheers, steve.

 

That's if you have a calibrated speedo.