New Tires

Agree with above, as to need to replace spare. Age matters, and a tire not being used, can become rotted, more so than one being run at highway speeds.

Only you know, how your spare has been treated. Out of sun, properly inflated, and not more than 10+ years old? Are you towing long distances, or full timing? IMO, unless you fall under one of above, I'd use the current spare, rather than buy new, just to hang on the trailer.

Jerry

My belief is that since the spare usually but not always is kept out of direct sunlight it should be good enough to continue being a spare for a while. My trailers have all had the spare underneath the frame and on the rare occasion that I needed to use or inspect it I found no cracks or obvious signs of deterioration. Age of the tire figures into the equation because after around 6 years they are not supposed to be used as a permanent tire. As with everything in our world right now tires are very expensive and buying 5 just to put one underneath as a spare is wasteful. But it depends on your financial situation and peace of mind. All of my spares on my RV and both boats are older tires that I have either pulled out of service or they came with the unit when new and I never replaced. I do however once a year check for dry rot and obvious knots or bulges or signs of separation. Keeping the lug nuts checked for proper tightness is more important than keeping new rubber as a spare!!