2 Meters though great where it works is not 100%.. If you are worried about being out in the middle of no where with a blown engine and no cell coverage that's not your best choice.. a Good multi-band HF radio (80-10 or 160-6) might be a better otpion. No the higher numbered (lower frequency) bands you may need more antenna than practical on an RV but for 40 or better 20 to six the antennas get smaller (a full Dipole is 1/2 the wavelength so a 20 meter Dipole is 10 meters or about 33.5 feet so reasonable on many RV's a Quarter wave VERTICAL is half that high
(The frame of the RV is the other half)
Range? Well some Rvers routinely work overseas contacts I routinely work about half the US voice and half the world digital when conditions are decent which right now they are not. but I can still talk to folks. Just not as many.