BMW M54 vs Skyactiv-G: which engine is more reliable?

According to our risk index, the Skyactiv-G carries less risk than the BMW M54: 25/100 (moderate risk) versus 54/100 (high risk). The BMW M54 has 2 documented serious faults, the main one being «Thermostat and water pump failure»; the Skyactiv-G has no documented serious faults.

Risk index

BMW M54

High risk · 2 serious faults

Risk index

Skyactiv-G

Moderate risk · 0 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 5 October 202612 sources How we work

Is the BMW M54 reliable?

The BMW M54 (2000-2006) is a naturally aspirated petrol inline-six with a reputation for longevity, passing 200,000 km if maintained. Its weak points are the crankcase ventilation valve and the plastic cooling system; check that they have been renewed.^[1][2][3]

See the 5 of the BMW M54 faults

Is the Skyactiv-G reliable?

The Skyactiv-G is a naturally aspirated petrol engine that the German specialist press consistently describes as reliable, with no documented pattern of serious engine faults in any Mazda model reviewed. Its weak point, shared with almost any direct-injection petrol engine, is carbon build-up in the intake; in addition, 2017-2020 units had recalls for software and for the fuel pump, since fixed by the manufacturer.^[4][5][6][7]

See the 5 of the Skyactiv-G faults

Side-by-side comparison

Comparison of BMW M54 and Skyactiv-G
Item	BMW M54	Skyactiv-G
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	—	—
Timing	Chain	Chain
Power	170–235 hp	75–187 hp
Production	2000–2006^[8][9]	since 2011^[4][10]
Reliability
Risk index (what is it?)	54High risk	25Moderate risk
Documented faults	5	5
Of high or critical severity	2	0
Worst severity	High severity	Medium severity
Main faults	High severity: Thermostat and water pump failure High severity: Cracked expansion tank and coolant leak Medium severity: Cracked crankcase ventilation valve (CCV) and oil consumption	Medium severity: Intake shut-off valve software issue and engine stalling Medium severity: Micro-cracks in the fuel pump impeller Medium severity: ECU programming and loss of power (CX-5 II and Mazda3 IV)
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	None	1.5 Skyactiv-G (P5-VPS)^[5][11] 2.0 Skyactiv-G (PE-VPS)^[6][7][12] 2.5 Skyactiv-G (PY-VPS)^[6]
With cautionVersions to be cautious about	M54B22, 2.2 litres (168-170 hp)^[1][2][3] M54B25, 2.5 litres (189-192 hp)^[1][2][3] M54B30, 3.0 litres (228-235 hp)^[1][2][3]	None
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 M54

Skyactiv-G

See the 9 models with the Skyactiv-G

Other comparisons

With the BMW M54

With the Skyactiv-G

Compare other engines

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Sources

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

BMW M54 Engine Guide: Reliability, Common Problems & Tuning PotentialEuro Premium Parts · Technical documentation · consulted 5 October 2026
Il motore da 6 cilindri che supera agilmente i 300.000 kmAutoblog.it · Motoring press · published 13 February 2026 · consulted 5 October 2026 · in Italian
BMW M54 reliabilityAutoscore · Other source · consulted 5 October 2026
SkyactivWikipedia (inglés) · Other source · consulted 27 September 2026
Mazda 3 (BM/BN, 2013-2019) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda 6 (GJ, III) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda CX-5 II (KF) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
BMW M54Wikipedia (inglés) · Other source · consulted 5 October 2026
BMW M54Wikipedia (alemán) · Other source · consulted 5 October 2026 · in German
List of Mazda enginesWikipedia (inglés) · Other source · consulted 27 September 2026
Mazda 2 (DJ) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda 3 IV (BP) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German