Since cars with air-cooled engines require a powerful cooling fan that requires more power than the water pump of a water-cooling system, the overall efficiency of air-cooled engines in cars is worse than that of water-cooled engines. Also, air-cooled internal combustion engines are generally mechanically louder than liquid-cooled engines due to the lack of noise-insulating water jacket, and an efficient interior heating is more difficult to realize. In addition, the operating temperature and thus the power and consumption of an air-cooled engine depends more on the current outside temperature, which is why many air-cooled vehicles still have an oil cooler with thermostat. In addition, components such as ducts, valves (valve angle), spark plugs and injectors can not be arranged arbitrarily in air-cooled cylinder heads, as it would require an optimal in-engine exhaust behavior, making it difficult to comply with modern emission regulations. Likewise, thermally highly loaded zones such as the area between the exhaust valve seats and spark plug can be better controlled in multi-valve arrangements with liquid cooling, which allows a higher compression ratio without knocking in favour of exhaust and fuel consumption. Air-cooled engines are therefore used increasingly less frequently in motor vehicles.

Automobiles such as the Porsche 911, the VW Beetle, the Trabant and the Citroën 2CV, but also trucks from Magirus-Deutz, Robur and Tatra were equipped with air-cooled engines. With motorcycles one finds air-cooled engines still quite frequently today. Companies such as Harley-Davidson, Buell, Ducati, Moto Guzzi or BMW have or have had numerous models with air cooling in the current program. As part of the EURO4 standard, many manufacturers have switched to water cooling. Further applications of the air-cooled engine are in propeller aircrafts and in RC cars with internal combustion engine.