BMW B38 / B37 vs 1.2 8v: which engine is more reliable?

According to our risk index, the BMW B38 / B37 carries less risk than the 1.2 8v: 20/100 (low risk) versus 36/100 (moderate risk). The BMW B38 / B37 has 1 documented serious fault, the main one being «B38 crankshaft thrust bearing failure (units before April 2015)»; the 1.2 8v has 1 documented serious fault, the main one being «Damaged cylinder head gasket (coolant loss and overheating)».

Risk index

BMW B38 / B37

Low risk · 1 serious fault

Lower risk

Risk index

1.2 8v

Moderate risk · 1 serious fault

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

Reviewed on 2 November 202617 sources How we work

Is the BMW B38 / B37 reliable?

BMW and MINI's three-cylinder B38 (petrol) and B37 (diesel) have no serious, widespread documented fault. The only problem reported in the press is the crankshaft thrust bearing on early B38 units (up to April 2015), corrected by BMW. BMW's EGR campaigns affect four- and six-cylinder diesels, not the B37.^[1][2][3]

See the 3 of the BMW B38 / B37 faults

Is the 1.2 8v reliable?

The 1.2 8v (D7F) is a simple naturally aspirated engine of 54 to 60 hp, with a timing belt, which Renault fitted from 1996 to the Twingo, Clio II and Kangoo. No catastrophic failures are documented; what owner reviews mention most often are the sensors, the cylinder head gasket, the coil packs and the occasional oil drip.^[4][5][6]

See the 5 of the 1.2 8v faults

Side-by-side comparison

Comparison of BMW B38 / B37 and 1.2 8v
Item	BMW B38 / B37	1.2 8v
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	1,499 cm³	1,149 cm³
Timing	Chain	Timing belt (dry)
Power	75–231 hp	54–60 hp
Production	since 2014^[7][8][9]	1996–2012^{[10][11][12][13]}
Reliability
Risk index (what is it?)	20Low risk	36Moderate risk
Documented faults	3	5
Of high or critical severity	1	1
Worst severity	Critical severity	High severity
Main faults	Critical severity: B38 crankshaft thrust bearing failure (units before April 2015) Medium severity: Coolant leaks and water pump or thermostat failure on the B38 Low severity: Carbon build-up on the B38's intake valves and injectors	High severity: Damaged cylinder head gasket (coolant loss and overheating) Medium severity: Crankshaft sensor (TDC) and other engine sensor failure Medium severity: Ignition faults: coil packs, ignition harness and humidity
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	B38 1.5 136-140 hp from April 2015 (B38A15 / B38B15)^[1] B37 1.5 diesel 95-116 hp (B37C15K0 / B37C15U0), up to 2017^[14] B37TÜ1 1.5 diesel 95-116 hp (from late 2017)^[15]	None
With cautionVersions to be cautious about	B38 1.2 (B38A12, MINI One)^[8] B38 1.5 136 hp up to April 2015 (B38A15)^[1] B38K15T0 231 hp (BMW i8)^[16]	1.2 8v 54-60 hp (D7F, 1996-2012)^{[4][5][6][17]}
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 B38 / B37

See the 17 models with the BMW B38 / B37

1.2 8v

Other comparisons

With the BMW B38 / B37

With the 1.2 8v

Compare other engines

First engine

Second engine

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.

BMW Dreizylinder: Dauertest-Probleme des B38 behoben?BimmerToday · Motoring press · published 5 October 2017 · consulted 4 October 2026 · in German
2024: BMW recall due to EGR coolers extended againcar-recalls.eu · Motoring press · published 28 March 2024 · consulted 4 October 2026
BMW diésel Europa: llamada a revisión por el EGR y riesgo de incendioDiariomotor · Motoring press · consulted 4 October 2026 · in Spanish
Fiabilité Renault Clio 2 : pannes et avis des propriétairesFiches-auto.fr · Motoring press · consulted 2 November 2026 · in French
Fiabilité Renault Twingo 1993-2006 : pannes et avis des propriétairesFiches-auto.fr · Motoring press · consulted 2 November 2026 · in French
Fiabilité Renault Twingo 2 (2007-2014) : pannes et avis des propriétairesFiches-auto.fr · Motoring press · consulted 2 November 2026 · in French
BMW B38 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026
BMW B38 (Wikipedia, alemán)Wikipedia · Other source · consulted 4 October 2026 · in German
BMW B37 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026
Moteur D (Renault)Wikipédia (francés) · Other source · consulted 2 November 2026 · in French
Renault Clio IIWikipedia (alemán) · Other source · consulted 2 November 2026 · in German
Renault TwingoWikipedia (alemán) · Other source · consulted 2 November 2026 · in German
Renault Twingo IWikipedia (alemán) · Other source · consulted 2 November 2026 · in German
Project one M: MINI Cooper D F56 fährt eine Million Kilometer in 12 JahrenBimmerToday · Motoring press · published 24 June 2026 · consulted 4 October 2026 · in German
BMW Baukasten-Diesel: Mehr Infos zur TÜ1 für B47 und B37BimmerToday · Motoring press · published 20 November 2017 · consulted 4 October 2026 · in German
BMW i8 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026
Renault Twingo (ab 1993): Schwachstellen laut TÜV-AuswertungAUTO BILD · Motoring press · published February 2002 · consulted 2 November 2026 · in German