i have 4 265/75/16 bridgestone dueler m/t's and 1 of them is brand new. the other three are not so new <img src="/forums/images/graemlins/frown.gif" alt="" />. i'd say they have 1/3rd of original tread. so i've heard that different sizes are bad because the "diff" will heat up because the different tire sizes spin at different speeds. so my question is if i run the tires as is for lets say 2 months will i burn my "diff" up??? please help i want these puppies on soon!