Nowadays, non-pneumatic tires are becoming an increasingly likely alternative to pneumatic tires. The function of compressed air has been taken over by the belt and the elastic structure (materials used and shape of the components). The research presented in the paper was carried out in quasi-static conditions. The research's aim was to compare the radial stiffness, hysteresis and selected parameters of the contact patch of two non-pneumatic tires and four pneumatic tires used interchangeably in ATVs/UTVs. Analizowane opony niepneumatyczne charakteryzują się większą sztywnością radialną niż opony pneumatyczne tego samego rozmiaru. The analyzed non-pneumatic tire with a cellular structure has the highest hysteresis of the radial characteristics of the tested wheels and the highest values of the unit pressure in the area of contact patch. The paper also verified two methods of calculating the contact patch length of non-pneumatic tires.