What sort of Instantaneous mpg figures does anyone get at full throttle in 3rd gear in a Fabia vRS?

I'm just curious really. I usually have it set to display average mpg but the other day I managed 11mpg instantaneous when joining the motorway on an uphill slip road.

This settled down to about 46mpg when cruising at 70mph in 6th on the flat.

Ok, Octy 110, but I've had the instantaneous display down to 8.3mpg instantaneous. At the other end, I've managed 850 before the fuel cutoff came right in.

Will try this on the way home ha