I need advice on tire maintenance?

Jack it up and then remove and store the wheels.

Store them in your fridge or better yet your freezer that should prevent rotting ! : P
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-1. Keep your RV’s tires covered when your RV is not in use. By covering the tires you are helping to slow down the tire damaging effects of Ultra Violet Light. Tire covers come in all shapes and sizes and there are tire covers for all types of RVs. Here are a couple of places to look to get a great selection of tire covers at excellent prices. RV Tire Covers From Amazon and RV Tire Covers Available From eBay.

2. Keep your RV tires clean. Dirt and oils can speed up the tire exteriorization of your tires. Clean them frequently.

A lot of RVer’s use and swear by a product called 303 Aerospace Protectant on their RV’s tires. 303 Aerospace Protectant provides Unsurpassed UV-screening protection. It is environmentally safe: Non-toxic, non-flammable, biodegradable, it sprays on easily, repels dust, soiling and staining. The treated surfaces stay cleaner, longer and it Lasts 4 to 10 times longer than other products. And if that is not enough you can also use this on your tire protectors to protect them from getting damaged. It is also recommended that you use this on the front and backs of your tires about once every two months.

3. Keep your tires properly inflated. Having too much or too little air in your RV’s tires will cause premature wear on the tires or create a tire blow out situation.