I suspect it's related to the slotted rear rotors especially if that is an upgrade. The fronts are designed much bigger to take the majority of the stopping energy and I suspect by improving the rear brakes they are doing more work than they used to.

I would definitively test out the front brakes with some firm braking on wet or sand etc to make sure they are locking up before or same time as the rear. Lock the front= under steer and slight loss of control, lock the back and spin around like a top it's why tire install locations are required to put a new pair on the back axle.

Coincidentally I'm replacing my wife's rear brakes today. We drove the car for about 1500 miles past the wear indicator and there is still about 3mm on the inside pad and about 2.5 on the outside pad. I don't know what thickness the pad is when the sensor is triggered but I'm estimating the new pads are about 8mm thick. Did you measure precisely? Often things can look quite different from the perspective or possibly the backing plate or is it possible the fronts started thicker?


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2011 E70 • N55 (me)
2012 E70 • N63 (wife)