While doing some research for selecting new tires for my MINI, I ran some numbers through the tire size calculator on the 1010 Tire web-site. I made an interesting discovery; which isn't going to matter to most owners, but still yet some interesting facts.

I used a MINI with 17" tires as a model, and used 36,000 miles as a milage figure.

Lets say that Mr. Bean purchases a new MINI with the standard 205/45/17 inch wheel/tire combo. He wants to do a little personalization to the MINI, so he decides to go with new wheels and tires right off the bat.

Stock 205/45/17 tires vs 215/45/17 tires:

When switching over to the larger tires, he has slowed his speedometer down by 1.443%. With the stock tires, at a speedometer reading of 60mph, the larger tires will only show a reading of 59.1mph. By the time he reachs 36,000 miles, his odometer reading will actually show 35,480.52 miles. He has gained 519 miles of warranty coverage.

Stock tires vs 205/40/17 tires:

If he switches over to the lower profile tires, he has sped up his speedometer readings by 3.452%. With a stock speedometer reading of 60mph the low profile tires will show a reading of 62mph. When the MINI's actual milage is 36,000 miles, his odometer reading will read 37,242.72 miles. He has lost 1242 miles of warranty coverage.

I know, I must have too much time on my hands to be thinking of stuff like this. But, it was interesting.

 

You're absolutely right, but keep in mind that there are variances in the accuracy of the stock speedometer also. People have reported a difference of up to 10% between actual speed and speedo readouts; granted, most have reported a far smaller discrepancy. Mr. Bean may gain/lose (most likely lose, since all speedos overstate mph) a fair amount of warranty coverage because of erroneous speedo readings.

Of course, he may counteract this by mounting super-low-profile tires on small-diameter rims, going as small as 195/40/16 for an almost 9% reduction in diameter.

 

I find this information distuuuurbing........

 

I knew there was a reason I should have paid more attention in Physics... Hated every minute