I have my own Excel spreadsheet to record exercise data (including that displayed by Zwift after a ride) and find that the Zwift Tour of Italy challenge is displaying 10% more distance than I have recorded. same data, different totals, Why and How?
That’s an interesting issue you bring up but it’s impossible to answer without a more detailed investigation. I highly recommend that you please submit a support request if you haven’t already done so, and a Zwift team member will be happy to take a closer look at this matter.
It would be helpful when submitting the support request if don’t mind sharing your own excel spreadsheet totals for the benefit of our team so we can measure it against the records listed in the Zwift activity on your dashboard, which we can reference. Also, please let us know what percentage you’re at on the Tour of Italy challenge. Thanks!