No they are not unless you plan to stay somewhere for two to three weeks or more. I dont put mine on the rv unless I plan a minimum of three weeks. The purpose of the covers is to prevent or slow down dryrotting from the sun.
Hey stevie, No to both. They are both best used while RV is in storage. Use some UV protectorate on the tires. It takes years for the sun to dry rot the tires. I've been out RV'ing for 13 years and have never used an air conditioner cover.