BMW N57 vs MZR-CD: which engine is more reliable?

According to our risk index, the MZR-CD carries less risk than the BMW N57: 64/100 (high risk) versus 87/100 (very high risk). The BMW N57 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 N57

Very high risk · 3 serious faults

Risk index

MZR-CD

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

Reviewed on 27 September 202619 sources How we work

Is the BMW N57 reliable?

The BMW N57 (2008-2019, successor to the M57) is a six-cylinder diesel that is mechanically robust in the basics, but it shares with the N47 and B47 the EGR cooler covered by BMW's service campaign for engine fire risk, and it inherits from the N47 the timing chain at the rear of the block, with wear cases documented mainly from 200,000 km. Without a clear history of these checks, it is worth buying with some caution.^[1][2][3]

See the 4 of the BMW N57 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.^[4][5][6][7]

See the 4 of the MZR-CD faults

Side-by-side comparison

Comparison of BMW N57 and MZR-CD
Item	BMW N57	MZR-CD
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	2,993 cm³	—
Timing	Chain	Timing belt (dry)
Power	204–381 hp	105–185 hp
Production	2008–2019^[1][8]	2002–2013^{[9][10][11][12][13]}
Reliability
Risk index (what is it?)	87Very high risk	64High risk
Documented faults	4	4
Of high or critical severity	3	3
Worst severity	Critical severity	Critical severity
Main faults	Critical severity: EGR cooler leaks with risk of engine fire Critical severity: Rear timing chain wear High severity: Loss of thrust on twin-turbo versions due to the vacuum circuit or the actuator	Critical severity: Timing chain stretch on the 2.2 MZR-CD High severity: Oil dilution from leaking injector seals and DPF regenerations High severity: Turbocharger wear or failure
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	None	None
With cautionVersions to be cautious about	N57D30 204-211 hp, single turbo (U0/UL, 2010-2013)^[3][14] N57D30 245-258 hp, single turbo (O0/O1, 2008-2019)^[3][14] N57D30 299-313 hp twin turbo (T0/T1, 2009-2019)^[14][15]	2.0 MZR-CD 121-143 (RF, 2002-2005, no DPF)^[4][6][16] 2.0 MZR-CD 105-143 (RF, 2005-2010, with DPF)^{[4][6][16][17]} 2.2 MZR-CD 125-185 (R2, 2008-2013)^{[5][7][18][19]}
AvoidVersions to avoid	None	None

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

Cars that each one is fitted to

BMW N57

See the 10 models with the BMW N57

MZR-CD

Other comparisons

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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.

BMW N57Wikipedia (inglés) · Other source · consulted 27 September 2026
Motor BMW B47 - Reparación EspecializadaDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
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 27 September 2026 · in Spanish
Fiabilité Mazda 6 (2002-2008)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité Mazda 6 (2008-2013)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Mazda 6 I: Bekannte Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Mazda 6 II: Bekannte Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
BMW N57Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Mazda diesel enginesWikipedia (inglés) · Other source · consulted 27 September 2026
Mazda6Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Mazda3Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Mazda5Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Mazda CX-7Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Motor BMW N57 - Reparación EspecializadaDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
Motor BMW N57: problemas, modelos y qué revisarCarexam · Motoring press · consulted 27 September 2026 · in Spanish
Fiabilité Mazda 3 (2003-2009)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Japanische Zuverlässigkeit? Ärger mit den Dieseln von Mazda und Toyotagebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Fiabilité Mazda 3 (2009-2013)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Mazda 3 II (2009-2013): Typische Probleme & Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German