Thin-Data Summary
Most dependable: The N52B30 3.0‑litre straight‑six (730i, 2009–2015) — a naturally aspirated, proven engine from the E90‑era BMWs — offers 255 hp, sublime refinement, and a proven 200,000‑mile reputation with few inherent weaknesses. The N57 3.0‑litre diesel (730d) is also robust and torque‑rich — many owners report 200,000+ miles with proper servicing. The N54 twin‑turbo (740i, pre‑LCI) carries the highest risk — HPFP and injector failures are well‑documented. The N63 V8 (750i) is characterful but suffers from oil consumption, turbo failures, and heat‑related issues. The N74 V12 (760Li) is a masterpiece but maintenance costs are eye‑watering. Buyers should prioritise a well‑maintained N52 or N57 with documented service history.







