BMW B38 / B37 vs 1.0 MPI: which engine is more reliable?

According to our risk index, the 1.0 MPI carries less risk than the BMW B38 / B37: 19/100 versus 20/100 (both low risk). The BMW B38 / B37 has 1 documented serious fault, the main one being «B38 crankshaft thrust bearing failure (units before April 2015)»; the 1.0 MPI has no documented serious faults.

Risk index

BMW B38 / B37

Low risk · 1 serious fault

Risk index

1.0 MPI

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 30 October 202619 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 1.0 MPI reliable?

The 1.0 MPI is a simple, low-powered (60-75 hp) naturally aspirated three-cylinder engine with no serious or systemic faults documented. Its most frequently cited issues are above-normal oil consumption -- especially in the Seat Ibiza V -- and, more occasionally, a cooling system fault with the engine light and vibrations. The timing belt has no fixed replacement interval and shows no failure pattern.^[4][5][6][7]

See the 4 of the 1.0 MPI faults

Side-by-side comparison

Comparison of BMW B38 / B37 and 1.0 MPI
Item	BMW B38 / B37	1.0 MPI
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	1,499 cm³	999 cm³
Timing	Chain	Timing belt (dry)
Power	75–231 hp	60–75 hp
Production	since 2014^[8][9][10]	since 2011^{[11][12][13][14]}
Reliability
Risk index (what is it?)	20Low risk	19Low risk
Documented faults	3	4
Of high or critical severity	1	0
Worst severity	Critical severity	Medium 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	Medium severity: Cooling system fault with engine light and vibrations Low severity: Higher-than-normal oil consumption (most cited on the Seat Ibiza V) Low severity: Timing belt with no fixed replacement interval
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^[15] B37TÜ1 1.5 diesel 95-116 hp (from late 2017)^[16]	1.0 MPI 60/75 (CHYA/CHYB, 2011-2023)^{[4][6][17][18]} 1.0 MPI 65/75 (CHYC/CPGA, 2017-)^[5]
With cautionVersions to be cautious about	B38 1.2 (B38A12, MINI One)^[9] B38 1.5 136 hp up to April 2015 (B38A15)^[1] B38K15T0 231 hp (BMW i8)^[19]	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 B38 / B37

See the 14 models with the BMW B38 / B37

1.0 MPI

See the 7 models with the 1.0 MPI

Other comparisons

With the BMW B38 / B37

With the 1.0 MPI

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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 et pannes de la Volkswagen UpFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Seat Ibiza (2017-)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Skoda CitigoFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
VW Up: Beliebtes Stadtauto im GebrauchtwagencheckGebrauchtwagenberater.de · Motoring press · published 22 March 2026 · consulted 27 September 2026 · in German
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
VW EA211Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Škoda FabiaWikipedia (inglés) · Other source · consulted 27 September 2026
VW Polo VWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
VW Polo VIWikipedia (alemán) · Other source · consulted 27 September 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
Fiabilité et pannes de la Seat MiiFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
Fiabilité et pannes de la Skoda Fabia 3Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
BMW i8 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026