I have just done the first calculated economy check on my new 2013 GD i30 1.6 CRDI Tourer.
Warning light came on with trip showing 62 miles to empty (100 km)
Distance since initial tank brimming : 714 miles (1150 km)
Trip Distance to empty : 46.9 miles (75 km)
Fuel added : 57.86 litres
Average speed for last tank : 36 mph (58 kph)
Trip economy : 57.5 mpg (4.9 l/100km)
Calculated economy : 56.13 mpg (5.03 l/100km)
Trip economy error : +1.37 mpg (+2.3%)
This included a long trip to Dorset totalling about 400 miles. The remainder being local journeys.
During this tank the DPF regenerated 3 times - at intervals of 262, 267 and 123 miles
This is about on par with my previous GD i30 hatch