We've all heard about BMW not doing pads & rotors together anymore under maintenance. If your pads are low, they will do them, but it's tough getting them to do rotors. I had both my pads done (separate visits) but because my warranty/maintenance are about to run out, I wanted to see how close to minimum spec the rotors were so I had them measure. The statement is:

Front rotor minimum spec is 28.4MM when replacing pads but 26.0MM when not replacing pads. Rear rotor minimum spec is 18.4MM.

My measurements after 4 years: front 28.2MM and rear 19.1MM.

My first question is why would rear minimum specs be different from fronts? I know they definitely seem to wear faster (as do the rear pads). My SA also said that I shouldn't worry about the rotors unless I start feeling they're warped (brake vibration, etc.). Hard to believe - what exactly should I be looking out for, because I won't be doing pads for another 3-4 years at this rate (25k miles in 4 years)? Surprising too, with my 80% local driving. What are the measurements of brand new rotors anyway?

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'08 X5 3.0si - Alpine White / Saddle Brown interior
Specs: Sport Pkg, Premium Pkg, Tech Pkg, Comfort Access, Aero Kit, Style 433 staggered 20s on Conti DWS
Mods: Carbon 35 tint, LED angel eyes, GP Thunder 7500k fogs, H&R 20mm/25mm spacers, clear reflectors, gunsmoke-tinted taillights
Coded: Digital speedo, windows/sunroof/tailgate close via keyfob

X5 pics at Flickr