That's largely due to the fact that scissor jacks tend to have lower weight capacities and lifting ranges than bottle jacks ...

A good floor jack is about the best upgrade any home mechanic can make. Photo credit: David Traver Adolphus / AutoGuid ...

Mohawk Lifts' SLT-2500 lifting table is capable of lifting 2,500 pounds, compared to the 2,000-pound capacity of Mohawk Lifts ...

Floor jacks and scissor jacks are designed to lift a car, not to keep it held up for a long period of time. They can and have failed, with unfortunate stories to go along with those events.