pneumatic car lift

[vavet]

Is there a reason why air is not the chosen power source for car lifts? It's compressible, I get that, but why is that bad?
As long as you rest the lift on the stops after raising it, this seems like a non-issue. 90 PSI against a 20 square inch piston gets you 1800 lbs of lifting force. It does not matter if this is air or hydraulic fluid. I suppose you could run into a problem with it moving too fast, but that could be adjusted.
What else?
You already need compressed air to release the brakes on most lifts. Why not power the lift cylinders with compressed air?

 

[66Caprice]

Hmm... A question to ponder over on a Friday. Nice!!

 

[mike in tucson]

Several reasons to not use air:
1. cylinder size: notice the air lift at the gas station is a cylinder oriented vertically?
Hard to locate a 14 inch dia cylinder horizontally under a lift
2. not everyone has the compressor that pumps enough volume to lift a pneumatic lift quickly.... buyers would ***** about speed (as they ***** about everything)
3. Hydraulics are somewhat safer since a line rupture with an incompressible liquid doesn't present the danger that a compressed air line rupture does