- [1] MANN-FILTER — Passenger car catalogue 2020/21
MANN+HUMMEL · DE · Europe · Printed pp. 35–37: E90/E91 engine codes. Applicability dates may group E92/E93 and export markets. · Consultato il 08/10/2026
- [2] BMW — 4 Series Coupé, 06/2013
BMW Group · EN · Europe · Technical specifications pp. 27–32: 428i, 435i, 420d; oil quantities. · Consultato il 08/10/2026
- [3] BMW — 4 Series Gran Coupé, 02/2014
BMW Group · EN · Europe · Technical specifications: 420i, 428i, 435i, 418d, 420d; body-specific oil quantities. · Consultato il 08/10/2026
- [4] BMW — spring 2015 range updates
BMW Group · EN · Europe · 418d Coupé and 420d modular diesel changes, March 2015. · Consultato il 08/10/2026
- [5] BMW — spring 2016 range updates
BMW Group · EN · Europe · 420i, 430i, 440i and 425d: March 2016, before the body facelift. · Consultato il 08/10/2026
- [6] BMW — 4 Series technical specifications, 01/2017
BMW Group · EN · Europe · Coupé, Convertible, Gran Coupé: power, displacement, gearbox and oil change. · Consultato il 08/10/2026
- [7] ADAC — BMW 4er 2013–2020 Diesel
ADAC · DE · Europe · History, engine specification table, EGR recall and underbody observations. · Consultato il 08/10/2026
- [8] BMW — 4er Coupé Betriebsanleitung VI/13
BMW AG — owner’s handbook · DE · Europe · Printed p. 80: service display, oil or maintenance table. · Consultato il 08/10/2026
- [9] BMW — 4er Coupé Betriebsanleitung VI/13
BMW AG — owner’s handbook · DE · Europe · Printed p. 200: service display, oil or maintenance table. · Consultato il 08/10/2026
- [10] BMW — 4er Coupé Betriebsanleitung VI/13
BMW AG — owner’s handbook · DE · Europe · Printed p. 201: service display, oil or maintenance table. · Consultato il 08/10/2026
- [11] BMW — 4er Coupé Betriebsanleitung VI/13
BMW AG — owner’s handbook · DE · Europe · Printed p. 202: service display, oil or maintenance table. · Consultato il 08/10/2026
- [12] BMW TIS — BMW Quality Longlife-04
BMW AG — TIS (archive) · EN · Europe · SI 11 03 04 (156) · revision 09/2005 · Consultato il 08/10/2026
- [13] BMW Technical training — N55 Engine
BMW of North America — Technical training (archive.org copy) · EN · USA · Initial print 02/10 · “Crankshaft” (timing chains) · “Oil Level” (oil quality sensor) · engine-level description · Consultato il 08/10/2026
- [14] BMW parts catalogue (ETK) — F20 M135i N55: timing and valve train, timing chain
bmwfans.info (copy of the BMW ETK parts catalogue) · EN · Europe · Group 11 · timing chain · Consultato il 08/10/2026
- [15] Neue Motorengeneration für das BMW 135i Coupé und das BMW 135i Cabrio
BMW Group · DE · Germany · Presse-Information (PDF attachment), pp. 1–3 · Consultato il 08/10/2026
- [16] BMW Betriebsanleitung — Der BMW 1er (Online-Version für Sach-Nr. 01 40 2 956 470)
BMW AG (copy hosted by kfz-handbuch.de) · DE · Germany · deutsch X/14 · p. 71 (Servicebedarf) · pp. 166–169 (Motoröl, freigegebene Motorölsorten) · pp. 172–174 (Wartung: CBS, Übersicht Wartungsumfänge) · Consultato il 08/10/2026
- [17] BMW UK Technical data — 2 Series Coupé [F22], March 2014
BMW Group UK · EN · United Kingdom · Engine type (N20B20U0, N55B30O0, N47D20U1, N47D20O1, N47D20T1), output, torque, gearbox, “Engine oil — exchange quantity” · Consultato il 08/10/2026
- [18] BMW — 335i Touring, fiche 03/2013
BMW Group · EN · Europe / marchés ACEA · 2 pages : caractéristiques moteur, boîte, puissance/couple et Engine oil capacity, note Oil change volume. · Consultato il 08/10/2026