I seem to remember Mitch ( I think it was) from Bauer Millet, just before they went under, saying (on Pistonheads) that whilst every previous model Corvette used US gallons for the MPG, even Euro spec ones, the C7 would be the first to use Imperial Gallons as well as US. I would check with Ian Allan Motors for confirmation though.
Hi Peter if you go into the settings the units can be selected imperial, US or metric. Just got back from Le Mans and used metric while i was there but switching back did an average of 30 MPG imperial that was at 130KPH most of the time so not bad did not even use Eco mode at that do not like it with autos can cause the converter 2 shudder and need flushing !! hope that helps Mick !!