A compressed air car can reach up to 40 miles per hour on compressed air alone. To get to highway speeds, a gas-powered engine or electric motor is required. However, compressed air cars are ideal for short trips and city traffic, because they can run almost entirely on compressed oxygen, which is free and plentiful in the city. A gas-powered engine will only be necessary occasionally, for when the car needs to reach higher speeds. Therefore, the first compressed-air cars could be available in the United States by mid-2019.
The air car has no propeller
The first compressed air cars were constructed in the 19th century by Pittsburgh resident Lee Barton Williams, who claimed to have driven them for 10 miles on gasoline before switching to compressed air. In spite of these claims, Williams refused to provide any technical information, and the invention was patented in 1940. Although a typical air car has no propeller, it does show two cylinder heads between the chassis frames, presumably storing compressed-air.
Remarks
A compressed-air car was built by a Pittsburgh man named Lee Barton Williams. He claimed that it started on gasoline and switched to compressed air after reaching 10 mph. In addition to this, he refused to divulge any technical details, so he did not publish the design of his car. However, his invention was later granted a US patent, and was manufactured by American Pneumatic in West Virginia. While this vehicle did not actually make it to market, it has a predicted range of 140 kilometers.