Not quite. It's about 3x. It also depends on whether you're talking fixed wing or rotary wings. A modern car might easily have 130 kW or more, and that's what

Not quite. It's about 3x. It also depends on whether you're talking fixed wing or rotary wings. A modern car might easily have 130 kW or more, and that's what a Cessna 172 has (around 180 hp). (Sure, a plane cruises at the higher end of that, while a car only uses that much to accelerate and cruises at the lower end of the range - still not a factor of 10x.) As another datapoint, a Diamond DA40 does around 28 miles per gallon (< 9 litres per 100 km) at 60% power cruise.