If I go to the annual report for my vehicle (link "View Annual Reports" at the bottom), I see:
Total km Tracked: 1,060
But it seems that miles are reported, not kms.
In fact I have 1706 kms which are ~1060 miles.
Other stats are wrong too, for example
Avg km/Fuel-up: 176.7 and Avg Price/km: €0,14
while in ministats are 284.4 and €0.085 respectively.
Even here the values looks like their miles counterparts.
So it seems that in the Annual Report some conversions are missing.