The actual relation between installed power and averaged actual fuel consumption, as averaged from the database of
spritmonitor :
Power vs. mileage - Spritmonitor.de
The fuel consumption numbers above the bars are in Liters per 100km (62.1 miles), so higher numbers also mean higher fuel consumption.
Engine power in kW is given below the bars, and indicates a range from -10 to +10 kW around the given value.