20,054 miles of mixed motoring completed in two years from new, and 1776.2 litres (usually ASDA 95) bought, giving 11.3 mpl or 51.3 mpg overall. The averages shown by the car's instruments are 54.1 mpg and 34 mph.
Just revisited this thread and looked at this post again. This indicates that the car's computer is about 5-6% optimistic and that over a long period.
My very small sample over my first refill indicated a 5% discrepancy as well.
This is much better than the 10% error in the following cars: Golf 1.9TDI, Civic 1.8 (petrol), Jazz 1.4 x 2. These cars were all manual. Is there anything in the theory that a CVT or, indeed, any automatic will produce a more accurate computer reading? Fewer variables as computers are in charge?
Somebody with more technical knowledge than me needed!