Look at the 11- or 12-digit DOT number molded into the inboard sidewall of your tires to find out how old they are. For tires made before 2000, the last three digits are the date, with two digits for the week and one for the year (278 would be the 27th week of '78, '88, or '98). For tires made after 2000, it's the last four digits (2702 would be the 27th week of 2002).
Most "cosmetic performance" tires (like BFG T/A's, etc.) are only "S" speed-rated (112 mph) and aren't made with premium materials; you have to go up to at least an "H" speed rating before you get an added nylon cap belt that will contain the underlying steel belt in the event of a ply separation. If your tires are over ten years old, trash 'em.