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BMW N62 / N63 vs Skyactiv-G: which engine is more reliable?

According to our risk index, the Skyactiv-G carries less risk than the BMW N62 / N63: 25/100 (moderate risk) versus 54/100 (high risk). The BMW N62 / N63 has 3 documented serious faults, the main one being «N63 oil consumption from worn valve stem seals»; the Skyactiv-G has no documented serious faults.

Risk index

BMW N62 / N63

54

High risk · 3 serious faults

Risk index

Skyactiv-G

25

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

18 sourcesHow we work

Is the BMW N62 / N63 reliable?

The N62 (naturally aspirated V8, 2001-2010) is considered a solid engine, with the coolant hoses and valve stem seals as points to watch. The N63 (twin-turbo V8, since 2008) has a worse reputation: oil consumption from the seals, the timing chain and coolant loss; the post-July 2013 N63TU is considered more reliable.[1][2][3][4][5]

See the 6 of the BMW N62 / N63 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.[6][7][8][9]

See the 5 of the Skyactiv-G faults

Side-by-side comparison

Comparison of BMW N62 / N63 and Skyactiv-G
BMW N62 / N63Skyactiv-G
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement——
TimingChainChain
Power272–450 hp75–187 hp
Productionsince 2001[3][10][11][12]since 2011[6][13]
Reliability
Risk index (what is it?)54High risk25Moderate risk
Documented faults65
Of high or critical severity30
Worst severityCritical severityMedium severity
Main faults
  1. High severity: N63 oil consumption from worn valve stem seals
  2. Critical severity: N63 timing chain stretch and guide breakage
  3. Critical severity: Additional turbo coolant pump with a risk of short circuit and fire
  1. Medium severity: Intake shut-off valve software issue and engine stalling
  2. Medium severity: Micro-cracks in the fuel pump impeller
  3. Medium severity: ECU programming and loss of power (CX-5 II and Mazda3 IV)
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versions
  • N62B48TU 4.8 naturally aspirated 355-367 hp (550i, 650i, 750i, X5 4.8i; 2005-2010)[2][4]
With cautionVersions to be cautious about
  • N62B36 3.6 naturally aspirated 272 hp (735i, 2001-2005)[1][4]
  • N62B40 4.0 naturally aspirated 306 hp (540i and 740i, 2005-2010)[1][5]
  • N62B44 4.4 naturally aspirated 320-333 hp (545i, 645Ci, 745i, X5 4.4i; 2001-2006)[1][5][16]
  • N62B48 4.8 naturally aspirated 360 hp (X5 4.8is, 2004-2006)[17]
  • N63B44O1 (N63TU) 4.4 twin-turbo 450 hp (2013-2019)[3]
None
AvoidVersions to avoid
  • N63B44O0 4.4 twin-turbo 408 hp (2008-2014)[3][18]
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 N62 / N63

See the 12 models with the BMW N62 / N63

Skyactiv-G

See the 9 models with the Skyactiv-G

Other comparisons

With the BMW N62 / N63

With the Skyactiv-G

Compare other engines

That is the comparison you are viewing: change one of the two engines.

Sources

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

  1. BMW 5er E60, E61 – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 26 April 2024 · consulted 8 October 2026 · in German
  2. BMW X5 E70 – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 5 January 2023 · consulted 8 October 2026 · in German
  3. BMW 5er F10, F11: Typische Probleme und SchwachstellenGebrauchtwagenberater.de · Motoring press · consulted 8 October 2026 · in German
  4. BMW 6er E63, E64 – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 5 January 2023 · consulted 8 October 2026 · in German
  5. BMW 650i: Gebrauchtwagen-TestAUTO BILD · Motoring press · published 4 December 2015 · consulted 8 October 2026 · in German
  6. SkyactivWikipedia (inglés) · Other source · consulted 27 September 2026
  7. Mazda 3 (BM/BN, 2013-2019) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  8. Mazda 6 (GJ, III) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  9. Mazda CX-5 II (KF) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  10. BMW N62Wikipedia (inglés) · Other source · consulted 8 October 2026
  11. BMW N63Wikipedia (inglés) · Other source · consulted 8 October 2026
  12. BMW N62Wikipedia (alemán) · Other source · consulted 8 October 2026 · in German
  13. List of Mazda enginesWikipedia (inglés) · Other source · consulted 27 September 2026
  14. Mazda 2 (DJ) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  15. Mazda 3 IV (BP) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  16. BMW 745i (E65): Test über 100.000 kmAUTO ZEITUNG · Motoring press · published 12 January 2018 · consulted 8 October 2026 · in German
  17. BMW X5 E53 – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 4 January 2023 · consulted 8 October 2026 · in German
  18. Fiabilité Bmw Serie 5 (2010-2016) (252 témoignages)Fiches-auto.fr · Owners' forum · consulted 8 October 2026 · in French