Date registered: Dec 2005
Vehicle: W211 E320 Bluetec R129 SL500 - $1300 car ........ Ford F350 6l
Location: CA Bay Area
Mentioned: 9 Post(s)
Quoted: 1168 Post(s)
UV is what ages the tires the most.
If you drive 40,000+ miles a year you don't really have to worry because in worse case scenario the tires will last for 4 years before cracking and you will wear them out before that, but lot of owners keep the tires for more than 5 years while parking on the open and that is where UV protection becomes important.