Automotive floor jacks are relatively small devices used to manually lift an end or corner of a car off of the ground. A good floor jack is an essential tool for anyone who frequently works on their car, though everyone should at least own a basic model for changing the occasional flat tire. There are a few important things to consider when selecting a jack, including the material it is made of, pump to travel ratio, and the weight capacity.Automotive floor jacks are generally made of two materials: steel and aluminum. Because steel is a less expensive metal than aluminum, it is more commonly used in budget jacks. While both metals are durable enough to lift a car, steel is far heavier, meaning that a cheaper steel jack is generally going to be much bulkier and more cumbersome than even a smaller aluminum model. The pump to travel ratio of a jack is a description of how far the car will be lifted each time the user pumps the attached handle. More expensive jacks will lift the car higher with each movement of the handle, meaning it takes less time and effort to lift the car to a workable position. The weight capacity is how much weight, usually in tons, a jack can lift. Each jack is rated based on this number, and while most can lift a standard car, those who frequently work on trucks and other larger vehicles should consider paying more for a higher weight capacity.Balancing the desired price with the features you want and need is very important when choosing between automotive floor jacks. With careful consideration, however, it should not be too difficult to find the jack you need for a price you can afford.