BMW Brake Rotor Guide

Rotor Types

Smooth (Plain) Rotors

• Standard OEM type
• Best all-around performance
• Longest lifespan
• Quietest operation
• Recommended for: Street driving, most applications

Drilled Rotors

• Holes drilled through the rotor face
• Originally designed for gas evacuation (less relevant with modern pads)
• Disadvantage: Stress risers around holes can cause cracking
• BMW uses drilled rotors on some M models from factory
• Recommended for: Appearance, light track use

Slotted Rotors

• Shallow grooves cut into the rotor face
• Helps evacuate gas and debris from pad surface
• Maintains consistent bite
• Slightly faster pad wear
• Recommended for: Track use, aggressive street driving

Slotted + Drilled (Combination)

• Both slots and holes
• Maximum gas/debris evacuation
• Highest risk of cracking under extreme heat
• Recommended for: Appearance (not ideal for heavy track use)

Rotor Brands

Brand	Type	Quality	Price Range
Zimmermann	OEM supplier	Excellent	€80-150/pair
ATE	OEM supplier	Excellent	€70-130/pair
Brembo	Premium aftermarket	Excellent	€100-200/pair
DBA	Performance	Very Good	€150-300/pair
StopTech	Performance	Very Good	€150-300/pair
EBC	Performance	Good	€100-200/pair

Rotor Sizing by Model

Model	Front	Rear
E46 325i	300x22mm	294x19mm
E46 M3	325x28mm	328x20mm
E90 335i	330x24mm	330x20mm
F30 340i	340x30mm	330x20mm
F80 M3	380x30mm	370x24mm
G80 M3	380x34mm	370x24mm

When to Replace

• Minimum thickness: Stamped on the rotor (e.g., "MIN TH 22.4")
• Measure with a micrometer — if at or below minimum, replace
• Scoring: Light scoring is normal; deep grooves require replacement
• Warping: Pulsation through brake pedal = warped rotor
• Cracking: Any visible cracks = replace immediately

Tips

• Always replace rotors in pairs (both fronts or both rears)
• Bed in new rotors with new pads (see brake pad bedding procedure)
• Clean new rotors with brake cleaner before installation (removes anti-rust coating)
• Torque wheel bolts to spec — uneven torque causes rotor warping