thats not always ture, even if the tires r the same size an same type.. they can have different weights ofcourse, hell even the same brand tires an same type an everything can have different weights.. right now on my race car i have 195/60R14 falken azenis tires all the way around my race car, we weighed the tires b4 they were mounted an one tire was half a pound heavier than the rest, thats 8 ounces :-/ makes a big difference, the point is u never know until u have the tires in ur hand an weigh tem for urself... then again unless ur doing some serious racing.. u dotn really need to be a detail nazi like me lol