Re: Tires as Fenders
On larger commercial vessels and tugs, tires are routinely used as fenders.
The good things about them are that they are nearly indestructible and cheap. They will be used for years in really harsh conditions without any problems. You can get them from the junkyard which is nice too.
There are many cons that you should be thinking about. The biggest one to me is that they will mark up your topsides unless you are really careful to isolate them. Due to the stiffness of even softer tires, you will find that the boat comes up much harder against the dock. Another issue is that they are very heavy and unwieldly. Everytime you pull them up over the rail, you will probably get soaked (drilling a drain hole will help some) and you are in for a workout. There are also the looks to think about.
Personally, I would buy a few high quality oversized fenders and go that route.