BMW M57 vs MZR-CD: which engine is more reliable?

According to our risk index, the BMW M57 carries less risk than the MZR-CD: 63/100 versus 64/100 (both high risk). The BMW M57 has 2 documented serious faults, the main one being «Broken intake swirl flaps»; the MZR-CD has 3 documented serious faults, the main one being «Timing chain stretch on the 2.2 MZR-CD».

Risk index

BMW M57

High risk · 2 serious faults

Lower risk

Risk index

MZR-CD

High risk · 3 serious faults

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

Reviewed on 27 September 202618 sources How we work

Is the BMW M57 reliable?

The BMW M57 (1998-2010) is a six-cylinder diesel with a reputation for great mechanical longevity, capable of exceeding 500,000 km when well maintained, but a good share of the versions built before 2008 -especially with an automatic gearbox- have metal swirl flaps in the intake that can break and wreck the engine; check whether the car has them and what condition they are in before buying.^[1][2][3]

See the 5 of the BMW M57 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 M57 and MZR-CD
Item	BMW M57	MZR-CD
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	—	—
Timing	Chain	Timing belt (dry)
Power	150–286 hp	105–185 hp
Production	1998–2010^[1][8]	2002–2013^{[9][10][11][12][13]}
Reliability
Risk index (what is it?)	63High risk	64High risk
Documented faults	5	4
Of high or critical severity	2	3
Worst severity	Critical severity	Critical severity
Main faults	Critical severity: Broken intake swirl flaps High severity: Crankcase ventilation (PCV) valve failure Medium severity: Cracked exhaust manifold	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	up to €300Faulty air flow meter on the BMW M57 (loss of power)Published figure^[14]	No reliable data
Which versions to buy
BuyRecommended versions	None	None
With cautionVersions to be cautious about	M57D25, 2.5 litres (150-197 hp, 2000-2010 depending on application)^[2] M57D30, first-generation 3.0 litres (177-193 hp, 1998-2006 depending on application)^[2] M57D30TU, first revision 3.0 litres (201-272 hp, 2001-2006)^[2] M57D30TU2, second revision 3.0 litres, aluminium block (204-286 hp, 2004-2010)^[2]	2.0 MZR-CD 121-143 (RF, 2002-2005, no DPF)^[4][6][15] 2.0 MZR-CD 105-143 (RF, 2005-2010, with DPF)^{[4][6][15][16]} 2.2 MZR-CD 125-185 (R2, 2008-2013)^{[5][7][17][18]}
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 M57

See the 10 models with the BMW M57

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 M57Wikipedia (inglés) · Other source · consulted 27 September 2026
Motor BMW M57 - Reparación EspecializadaDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
BMW M57D30 engine specifications, problems and reliabilityBimmerPulse · Technical documentation · consulted 27 September 2026
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 M57Wikipedia (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
Caudalímetro o sensor MAF: qué es, cómo funciona y cuáles son las averías más frecuentesDiariomotor · Motoring press · consulted 30 October 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