Update: I bumped my air compressore to 120 psi. And it does lift my truck. I tried this air jack today. I'm restoring a 1992 chevy k1500. I wanted to move the truck over with dollies under the tires, I used the air jack to lift the rear first, no problem, I then tried to lift the front of the truck and it would not lift it off the floor, I had 115 psi of air and it wouldn't lift it. I doubt my truck (front only) weighs 3000 lbs. The max air pressure is 145psi. for this jack. It would be nice to have a chart to show how much air psi it takes to lift in 1000 lb incurments.