A 3.0-ton jack can safely lift up to around 3,500.0 pounds. If the thing you’re lifting is significantly lighter than that, you may not need a 3.0-ton jack. If the thing you’re lifting weighs more than 3,500.0 pounds, you’ll need a stronger jack.
If you’re lifting a car, keep in mind you may only need to lift one side of the vehicle, so if your car weighs 7,000.0 pounds, a 3.0-ton floor jack can raise it enough to change a flat tire or perform oil changes.