Necessity is the mother of invention, especially as fuel prices inch ever higher. A European manufacturer has developed a car that runs on compressed air, the Associated Press reported last week.Dubbed the Air Car by Luxembourg-based Motor Developpement International, an electric pump inside the car compresses air into a tank. The air then pumps pistons, which enables the car to travel up to 70 mph, according to the report. The car logs 50 miles at top speed on a full tank, and farther at lower speeds. The electric pump can be recharged in any socket and requires four hours to recharge.There will be two versions of the Air Car – a three-seat compact will cost $9,850 and a six-seat sedan will go for $16,000. A more expensive version is also available using a combination of compressed air and conventional gasoline that can travel faster and go farther. There are no plans as of yet to bring this kind of technology to the United States, but interest is high in France where it will initially go on sale. Production is expected to begin in June.