Keep in mind that tire size affects "indicated" speed and miles. So as your tires wear (get smaller), your speedometer and odometer will err on the high side. This is most notable right before and after you get new tires. So basically, if you are using your odometer to measure miles traveled, it is likely an overestimate if your tires are worn. This is one of the reasons some here suggest using GPS to accurately determine miles traveled in mpg calcs.

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1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).