[Beav]

You have to consider what causes them to warp. Many will tell you the same tried and true story of "Subaru never built a car this heavy before, that's why they warp so easy." While there may be some truth to this, it's not the complete story.

Rotors are cast iron and susceptible to density variation, in other words certain areas of the rotor may have more or less molecules of iron than other areas. As the different areas heat and cool at different rates the rotor expands and contracts differently, thus creating lateral run-out. The quality of the manufacturing process added to the driver's usage determines how often and how much warpage will occur.

When I lived in the mountains it used to kill me (laughingly) how easy it was to spot new residents by their driving skills. Newbies had to use their brakes at every single curve - going uphill. Nothing like taking your foot off of the gas a second or two earlier and letting gravity do the job...