I think the older Versa uses an older JATCO CVT than the current Versa. The newer CVT-7 transmission (used in several other cars like Chevy Spark & Mitsubishi Mirage) has a wider gear ratio, with lower RPM highway cruising for even better fuel economy.
jgoedhard - I don't supposed you checked actual distance between 2 stops via GPS to see which (or both?) cars' odometers were off?
View my fuel log 2015 Micra S manual: 5.0 L/100 km ... 56.5 mpg (Imp) ... 20.0 km/L ... 47.0 mpg (US) ...