alt Hacker NewsMythbusters lifted a 2 ton car using a consumer grade vacuum cleaner. the math is this: the air pressure over 1 sq meter is about 10 tonnes, so if make a box with that area and reduce the pressure by 0.25 atm, you get a force of equivalent to 2.5 tonnes, enough to lift the car.
https://www.youtube.com/live/GbqKwPktCdo?xstg=CAMSBhUDze3xHw...
I'm surprised a vacuum company didn't beat them to it. That would have made a pretty great marketing campaign ("the vac with enough suction to lift a car").