BMW B58 vs 1.2 8v Fire: which engine is more reliable?

According to our risk index, the 1.2 8v Fire carries less risk than the BMW B58: 20/100 (low risk) versus 38/100 (moderate 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 8v Fire has no documented serious faults.

Risk index

BMW B58

Moderate risk · 1 serious fault

Risk index

1.2 8v Fire

Low 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 9 October 202617 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 8v Fire reliable?

The 1.2 8v Fire is one of Fiat's simplest and most widespread petrol engines, with more than two decades in production and no serious or systemic faults documented. The sources consulted describe it as robust: its most-cited issues are isolated sensor failures (lambda sensor, crankshaft sensor), the ignition coil and somewhat high oil consumption at higher mileages; there is no pattern of timing belt breakage.^{[5][6][7][8][9][10]}

See the 4 of the 1.2 8v Fire faults

Side-by-side comparison

Comparison of BMW B58 and 1.2 8v Fire
Item	BMW B58	1.2 8v Fire
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	2,998 cm³	1,242 cm³
Timing	Chain	Timing belt (dry)
Power	290–441 hp	60–69 hp
Production	since 2015^[11][12]	1999–2020^{[13][14][15][16]}
Reliability
Risk index (what is it?)	38Moderate risk	20Low risk
Documented faults	6	4
Of high or critical severity	1	0
Worst severity	High severity	Medium 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)	Medium severity: Sensor failures: lambda sensor and crankshaft position sensor (TDC) Low severity: Oil consumption or leak, in one case from the rocker cover gasket Low severity: Faulty ignition coil (misfire, engine warning light)
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	B58TU2 381 hp (B58B30M2, since 2022)^[2][3]	1.2 8v SMPI 60-65 hp (1999-2009)^[5] 1.2 8v VVT 69 hp (2007-2020)^{[6][7][9][10]}
With cautionVersions to be cautious about	B58 326 hp (B58B30M0, 2015-2019)^[2][3][17] B58 340-360 hp (B58B30M0, 2016-2019)^[2][3][17] B58TU 333-340 hp (B58B30M1, since 2018)^[2][3] B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)^[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 B58

See the 15 models with the BMW B58

1.2 8v Fire

See the 7 models with the 1.2 8v Fire

Other comparisons

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With the 1.2 8v Fire

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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
Fiabilité et pannes de la Fiat Panda (2003-2012)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Fiat Panda (depuis 2012)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Fiat 500Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Fiat Punto (Grande Punto / Punto Evo / Punto)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiat Panda III (seit 2011) – Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · published 21 January 2023 · consulted 27 September 2026 · in German
Fiat 500 (ab 2007) – alle bekannten Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · published 24 November 2023 · consulted 27 September 2026 · in German
BMW B58Wikipedia (inglés) · Other source · consulted 9 October 2026
BMW B58Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
Fiat FIRE engineWikipedia (inglés) · Other source · consulted 27 September 2026
Fiat 500 (2007)Wikipedia (inglés) · Other source · consulted 27 September 2026
Fiat Grande PuntoWikipedia (inglés) · Other source · consulted 27 September 2026
Ford KaWikipedia (inglés) · Other source · consulted 27 September 2026
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