I also carry a two stage bottle jack, it has an extended lift range.It is the jack that came new with my F-550 work truck.I have changed tires on our dodge DRW 3500 and camper With the factory screw jack without problems but Personally the bottle jack just seams a bit more dependable and with the higher capacity rating it is much easier to operate. I also use my 2x6 leveling boards to extend lift range if needed.
On another note for you folks with 19.5 G or H rated tires,I have tried to make emergency repairs with the temporary plug kits.I never was very successful with getting the plugs to pass through the injury without destroying them,I guess there are so many steel plies they are very tough.I purchased a high quality plug kit from a tire dealer that repairs tires on the big rigs,still only had limited success.Any one else had this problem or is it something I am doing wrong?