The jack only has 4.75" of throw. This is the distance it will actually lift something. The length of the piston fully extended.  It also has a 2.25" screw out extension that will help you get the most out of the limited throw, but will not actually lift anything. If your sidewall is more than 5" high and you have a complete flat this little fellow will not raise your axle enough to get the new wheel and tire on. This jack will be fine if you are running 30 series tires but for anything taller I'd look elsewhere.