What will changing from the stock 205/45/17 to a 215/40/17 do to your speedometer accuracy? How much wider is the 40 than the 45?

 

>>What will changing from the stock 205/45/17 to a 215/40/17 do to your speedometer accuracy? How much wider is the 40 than the 45?

Here's a useful URL for calculating speedo effects of different tire sizes.

 

Right On.... Thank you for the link.

 

>>What will changing from the stock 205/45/17 to a 215/40/17 do to your speedometer accuracy? How much wider is the 40 than the 45?

The diameter diviation is .4 inches, or 1.02%, a very small shift in speedometer accuracy.

the 40 or 45 are representatve of sidewall height. the 1st number is the width of the tire in millimeters. The aspect ratio (middle number) is a persentage of the 1st number.

Alex