Any type of silicon spray will work well on tires to keep the "Harful UV Rays >
" from drying out the side walls. Not a bad idea to spray both sides of the tires. What kind of ground/pavement are you parking it on. If black top, would recommend pulling onto small pieces of wood (plywood is great) to keep the tire tread off of the extra heat generated by the blacktop and sun.
Most tire protectants use very little spray to cover the tire. You can (
) get quite a few applications from the can.
ColoradoCop