BMW B58 vs 1.2 12V: which engine is more reliable?

According to our risk index, the BMW B58 carries less risk than the 1.2 12V: 38/100 (moderate risk) versus 57/100 (high risk). The BMW B58 has 1 documented serious fault, the main one being «Failure of the oil pump with a plastic rotor housing»; the 1.2 12V has 2 documented serious faults, the main one being «Timing chain stretch and tensioner wear».

Risk index

BMW B58

Moderate risk · 1 serious fault

Lower risk

Risk index

1.2 12V

High risk · 2 serious faults

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

Reviewed on 9 October 202616 sources How we work

Is the BMW B58 reliable?

The B58 (3.0 turbo straight-six, since 2015) is considered robust and less troublesome than the N54/N55 it replaced, and the sources do not document widespread internal failures. The known faults are on the periphery: the plastic oil filter housing, crankcase ventilation, gaskets and coolant. On units built before 2021 there are also US reports of an oil pump with a plastic housing.^[1][2][3][4]

See the 6 of the BMW B58 faults

Is the 1.2 12V reliable?

The 1.2 12V is a simple, low-power, naturally aspirated three-cylinder engine (54-70 hp), with two documented design faults: the timing chain tensioner, which can end up destroying the engine, and -on the Volkswagen Polo IV- a catalytic converter too close to the cylinder head that can burn the exhaust valves. Ignition coil failures are also common, and there are isolated cases of oil consumption and vibration.^{[5][6][7][8][9]}

See the 5 of the 1.2 12V faults

Side-by-side comparison

Comparison of BMW B58 and 1.2 12V
Item	BMW B58	1.2 12V
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	2,998 cm³	1,198 cm³
Timing	Chain	Chain
Power	290–441 hp	54–70 hp
Production	since 2015^[10][11]	2001–2014^[5][12][13]
Reliability
Risk index (what is it?)	38Moderate risk	57High risk
Documented faults	6	5
Of high or critical severity	1	2
Worst severity	High severity	Critical severity
Main faults	High severity: Failure of the oil pump with a plastic rotor housing Medium severity: Oil and coolant leak from the plastic oil filter housing Medium severity: Failure of the crankcase ventilation PCV valve (integrated in the valve cover)	Critical severity: Timing chain stretch and tensioner wear High severity: Cylinder head and valve damage from exhaust gas backflow (Volkswagen Polo IV) Medium severity: Higher-than-normal oil consumption
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	B58TU2 381 hp (B58B30M2, since 2022)^[2][3]	None
With cautionVersions to be cautious about	B58 326 hp (B58B30M0, 2015-2019)^[2][3][14] B58 340-360 hp (B58B30M0, 2016-2019)^[2][3][14] B58TU 333-340 hp (B58B30M1, since 2018)^[2][3] B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)^[3]	1.2 54/60 hp (AWY, BMD, BBM, 2001-2014)^[5][7] 1.2 64/70 hp (BME, CGPA, 2002-2014)^{[5][7][15][16]}
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 B58

See the 16 models with the BMW B58

1.2 12V

See the 8 models with the 1.2 12V

Other comparisons

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With the 1.2 12V

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Sources

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

The 5 Most Common BMW B58 Engine ProblemsBMW Tuning · Technical documentation · published 7 February 2020 · consulted 9 October 2026
BMW B58 EngineFCP Euro · Technical documentation · consulted 9 October 2026
The Popular BMW B58 Inline-Six Engine Has One Big Achilles HeelThe Autopian · Motoring press · published 14 June 2024 · consulted 9 October 2026
¿En qué se diferencian los motores B58 y S58 de BMW?Diariomotor · Motoring press · published 27 April 2024 · consulted 9 October 2026 · in Spanish
VW Polo 4 (9N): Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Fiabilité et pannes de la Volkswagen Polo 4Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Seat Ibiza (2008-2017)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Seat Ibiza III (2002-2008): Bekannte Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Fiabilité et pannes de la Seat Ibiza (2002-2008)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
BMW B58Wikipedia (inglés) · Other source · consulted 9 October 2026
BMW B58Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
VW EA111Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
VW Polo IVWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
How A Plastic Part On BMW's B58 Engine Can Turn An Oil Change Into A $3,000 RepairThe Autopian · Motoring press · published 28 March 2025 · consulted 9 October 2026
Fiabilité et pannes de la Volkswagen Polo 5Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Skoda Fabia 2Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French