Fuel numbers readout?
 

When looking for a bike or automobile's gas mileage,
do the numbers show as US or IMP MPG?

Some numbers vary from 45MPG to 72MPG (or more), and it seems odd that there would be so much difference between them...?

Depends on your settings. Check the top left corner of the screen, there's a small drop down menu where you can select US MPG, UK MPG or other popular measurements.