Jack for changing flats?

It can be very difficult to loosen lug nuts unless you have a lug wrench plus pipe extension to break them loose. Using a bottle jack on soft dirt/gravel to lift an RV enough can be dangerous. Best to wait for an emergency road service unless you are well equipped and know how to change tires safely. Tell road service about whether you have or don't have a spare wheel/tire. Carrying a spare loose in your RV "trunk" can be dangerous and inconvenient. Have tires checked for serious side wall cracking especially after tires are five years old by date codes on tires. If you hear or feel steady thumping, stop and have tires inspected for tread separation. When a tire comes apart, flailing steel belts can seriously damage underside parts of the RV and you might lose control.