DELPHI brake disc (BG3870) is precision-machined from high-grade grey cast iron for uniform heat dissipation and resistance to thermal cracking under heavy braking. Key dimensional data — Test Mark: E1 90R-02C0074/1613, Height [mm]: 77 mm, Brake Disc Type: Carbon, Brake Disc Thickness [mm]: 24 mm — ensures the rotor geometry meets OEM tolerances for run-out, thickness, and parallelism right out of the box. Compatible with BMW vehicles; the hub-centric bore and bolt-circle pattern match the original specification exactly. Direct replacement for OE references: 0 986 479 055, 0 986 479 S29, 09.9173.11, 09.9173.14 and 57 more. DELPHI rotors are checked for surface hardness and dynamic balance before dispatch, keeping braking distances predictable throughout the service life of the disc. Brake discs generally last 50,000–70,000 miles, though this varies with driving habits, terrain, and pad compound — heavy urban driving or towing shortens disc life considerably. Warning signs of worn discs include visible scoring or lip formation on the friction surface, vibration through the steering wheel under braking, and a persistent grinding noise even with new pads fitted. Disc replacement is an intermediate DIY task; you will need a torque wrench, a breaker bar (some hub-to-disc retaining screws seize over time), and a jack with axle stands — budget 1–2 hours per axle. When selecting brake discs, check that the disc type (vented or solid) matches the original, and look for a protective anti-corrosion coating on the hub and non-friction surfaces to prevent rust jacking. Always replace discs in pairs (both sides of the same axle) to maintain even braking balance, and bed in new discs with the manufacturer's recommended gentle-braking procedure for the first 200 miles. Every part is dispatched from our UK warehouse with a 30-day money-back guarantee and free hassle-free returns.

Delphi Technologies, with roots dating back to 1994 as part of General Motors, is a globally recognised supplier of fuel injection, ignition, and engine management systems. Delphi specialises in diesel injectors, fuel pumps, ignition coils, lambda sensors, and engine management components. As an OE supplier to major manufacturers worldwide, Delphi products are engineered to original factory specifications. With deep expertise in both petrol and diesel fuel systems, Delphi is the professional's choice for precision engine and fuel system components.