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MotorFiable

BMW B47 vs MZR-CD: which engine is more reliable?

According to our risk index, the MZR-CD carries less risk than the BMW B47: 64/100 versus 73/100 (both high risk). The BMW B47 has 3 documented serious faults, the main one being «EGR cooler leaks with risk of engine fire»; the MZR-CD has 3 documented serious faults, the main one being «Timing chain stretch on the 2.2 MZR-CD».

Risk index

BMW B47

73

High risk · 3 serious faults

Risk index

MZR-CD

64

High risk · 3 serious faults

Lower risk

The index (0–100) weights the severity and frequency of the three most serious documented faults. How it is calculated

17 sourcesHow we work

Is the BMW B47 reliable?

The BMW B47 (since 2014, successor to the N47) improves the timing chain tensioner, guides and oil supply and greatly reduces the failure rate of its predecessor, but it is not free of problems: the EGR cooler has been the subject of several BMW technical campaigns for engine fire risk since 2018, and the turbo and particulate filter need careful maintenance.[1][2][3][4]

See the 4 of the BMW B47 faults

Is the MZR-CD reliable?

The MZR-CD is Mazda's most widespread diesel between 2002 and 2013, fitted to the Mazda3, Mazda6, Mazda5 and CX-7. It is sensitive to short journeys: the injector seals and incomplete DPF regenerations can dilute the oil, and the EGR and intake build up carbon. The 2.2-litre redesign (from 2008), with a timing chain instead of a belt, adds the risk of that chain stretching and damaging the engine.[5][6][7][8]

See the 4 of the MZR-CD faults

Side-by-side comparison

Comparison of BMW B47 and MZR-CD
BMW B47MZR-CD
Technical data
TypeEngineEngine
FuelDieselDiesel
Displacement1,995 cm³—
TimingChainTiming belt (dry)
Power114–228 hp105–185 hp
Productionsince 2014[1]2002–2013[9][10][11][12][13]
Reliability
Risk index (what is it?)73High risk64High risk
Documented faults44
Of high or critical severity33
Worst severityCritical severityCritical severity
Main faults
  1. Critical severity: EGR cooler leaks with risk of engine fire
  2. High severity: Timing chain wear (improved, but is it really at the front?)
  3. High severity: Premature turbo wear from neglected maintenance
  1. Critical severity: Timing chain stretch on the 2.2 MZR-CD
  2. High severity: Oil dilution from leaking injector seals and DPF regenerations
  3. High severity: Turbocharger wear or failure
Most expensive documented repairup to €2,000Premature turbo wear from neglected maintenancePublished figure[3]No reliable data
Which versions to buy
BuyRecommended versionsNoneNone
With cautionVersions to be cautious about
  • B47 114-150 hp, single turbo (2014-)[2][4]
  • B47 168-190 hp, single turbo (2014-)[2][4]
  • B47 202-228 hp, twin-turbo (2015-)[2][4]
  • B47C20 (MINI Cooper D/SD and Countryman, 2014-)[1][4]
AvoidVersions to avoidNoneNone

Severity of each fault: green, low; amber, medium; red, high; dark red, critical. How we rate them

Cars that each one is fitted to

Other comparisons

With the BMW B47

With the MZR-CD

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Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. BMW B47Wikipedia (inglés) · Other source · consulted 26 September 2026
  2. 324.000 diésel de BMW tendrán que pasar por el taller en Europa, por un posible riesgo de incendio en la EGRDiariomotor · Motoring press · published 8 August 2018 · consulted 26 September 2026 · in Spanish
  3. Motor BMW B47: problemas, modelos y qué revisarCarexam · Motoring press · consulted 26 September 2026 · in Spanish
  4. Motor BMW B47 - Reparación EspecializadaDasercars · Technical documentation · consulted 26 September 2026 · in Spanish
  5. Fiabilité Mazda 6 (2002-2008)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  6. Fiabilité Mazda 6 (2008-2013)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  7. Mazda 6 I: Bekannte Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
  8. Mazda 6 II: Bekannte Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
  9. Mazda diesel enginesWikipedia (inglés) · Other source · consulted 27 September 2026
  10. Mazda6Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  11. Mazda3Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  12. Mazda5Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  13. Mazda CX-7Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  14. Fiabilité Mazda 3 (2003-2009)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  15. Japanische Zuverlässigkeit? Ärger mit den Dieseln von Mazda und Toyotagebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
  16. Fiabilité Mazda 3 (2009-2013)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  17. Mazda 3 II (2009-2013): Typische Probleme & Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German