[evldave]

I believe there is a federal law that requires the speedometer, from the factory, not be more than x% below the actual speed (don't know the value). This is so you can be absolutely sure you aren't going faster than indicated on the speedo. Mfrs adjust their speedos high (low) to make sure they meet the guidelines.

Also, European regs have a tighter guidelines, meaning they are more restrictive for the 'too high' guidelines. So EU mfrs adjust their speedos high (so your speed is lower than indicated) even more - my BMW was 3-4 mph low, I checked the H3 on the way home from work today and it was 1-2 mph low.

So why does that matter? Because no math you can do will adjust for the factory fudge, so just wing it. Since the factory builds in a fudge, technically your odometer is off anyway, so an extra bit here or there is moot.