[CapriRacer]

I see I generated some interest and comments.

1) This test was about using the measured circumference to directly calculate the revolutions per mile. I said there was a 3% difference.

I supposed one could use the same technique to measure the difference between a lightly loaded tire and a heavily loaded tire, but that was NOT what was going on here. I don't think the difference in loading for this set of measurements is enough to draw conclusions.

2) The photo of the tape wrapped around the tire is a little misleading. I needed 3 hands to take the photo - the third had holding the tape against the tire - and had I done that, the photo would have shown the 2" mark closer to the 1/8" mark. So the measurement was 7 feet 1/8 inch minus 2 inches. (Remember that 2" thing for #4 below)

3) How did I assure I did one complete revolution? There was tape applied to each tire when it was in the air - and I marked it with a radial line. I rotated the tire such that it was close to the footprint and lowered the car off the jack, then pushed the vehicle until the tape was in contact with the floor and as nearly vertical as I could make it. I then applied a strip of tape on the ground and mark the line. The photo shows one of those! There are 2 strips of tape in that photo.

I then pushed the vehicle back watching the tape and when the tape reached vertical again, I stopped, applied another strip of tape to the floor and marked the tape again. I used a block of wood to help fine tune the position. (see the photo of the tape on the floor.

4) Remember that 2" mark - the first mark on the tape? I used that for the "Zero", which meant I had to subtract 2" from each reading I took. The photo shows a measurement of 82 1/8", but the actual length is 2" shorter than that. My measurements were as reported.

5) And, No, I made no comment about the changes tire wear has on revs/mile. I have heard that worn tires have smaller rolling diameters, but have no direct knowledge that is so. This set of measurements doesn't demonstrate anything in that regard.

And Teleman, even if your supposition is correct, your calculations are wrong because they don't show the 3% difference I demonstrated above.

I hope that addresses all the question.