My Golf 1.9 TDI, 5-speed manual, originally 90 hp but now remapped with bigger nozzles (about 135 hp and 225+ pounds of torque), gets about 42 miles per US gallon in the winter and about 38 miles per US gallon in the summer (AC usage plus hot fuel causes retarded timing). So 40 mpg overall, or about 48 miles per Imperial gallon.
About 50-50 between urban and highway driving. If I spent more time on the highway, but drove slower than my normal 75-80 mph, my fuel mileage would improve. The best I ever saw was 52 miles per US gallon (63 miles per Imperial gallon) for two consecutive tanks on a long road trip. On one of those tanks I traveled just over 800 miles.