BMW B38 / B37 vs 1.2 Dualjet and 1.2 VVT: which engine is more reliable?

According to our risk index, the BMW B38 / B37 carries less risk than the 1.2 Dualjet and 1.2 VVT: 20/100 versus 23/100 (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 1.2 Dualjet and 1.2 VVT has no documented serious faults.

Risk index

BMW B38 / B37

Low risk · 1 serious fault

Lower risk

Risk index

1.2 Dualjet and 1.2 VVT

Low risk · 0 serious faults

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

Reviewed on 30 October 202616 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 Dualjet and 1.2 VVT reliable?

The Suzuki 1.2 VVT and 1.2 Dualjet (K12B/K12C/K12M) is a naturally aspirated petrol engine with a timing chain and indirect injection, fitted since 2008 to the Splash, Swift, Ignis and Baleno, with an SHVS mild-hybrid variant since 2016. It is reliable: there is no serious documented fault with the engine block itself; the main points are a clutch that wears out sooner than expected on some cars and two SHVS recalls that have already been resolved.^{[4][5][6][7][8]}

See the 5 of the 1.2 Dualjet and 1.2 VVT faults

Side-by-side comparison

Comparison of BMW B38 / B37 and 1.2 Dualjet and 1.2 VVT
Item	BMW B38 / B37	1.2 Dualjet and 1.2 VVT
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	1,499 cm³	—
Timing	Chain	Chain
Power	75–231 hp	82–92 hp
Production	since 2014^[9][10][11]	since 2008^[4][5]
Reliability
Risk index (what is it?)	20Low risk	23Low risk
Documented faults	3	5
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: Clutch: premature wear and clutch cable anchor failure Medium severity: SHVS mild-hybrid system: recalls for the starter generator belt and software Medium severity: Water pump pulley fixing (2013-2014): recall
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^[12] B37TÜ1 1.5 diesel 95-116 hp (from late 2017)^[13]	1.2 VVT 86-92 hp (K12B, one injector per cylinder, 2008-2013)^[7] 1.2 Dualjet non-hybrid 89-91 hp (K12B/K12C, dual injector, 2013-2020)^[8][14][15] 1.2 Dualjet SHVS mild hybrid 82-90 hp (K12C/K12D, since 2016)^[8]
With cautionVersions to be cautious about	B38 1.2 (B38A12, MINI One)^[10] B38 1.5 136 hp up to April 2015 (B38A15)^[1] B38K15T0 231 hp (BMW i8)^[16]	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

1.2 Dualjet and 1.2 VVT

See the 7 models with the 1.2 Dualjet and 1.2 VVT

Other comparisons

With the BMW B38 / B37

With the 1.2 Dualjet and 1.2 VVT

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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
Suzuki motor KWikipedia · Other source · consulted 27 September 2026 · in Spanish
Suzuki K engineWikipedia · Other source · consulted 27 September 2026
Suzuki Swift (NZ) – Typische Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Suzuki Splash (2008–2014) – Bekannte Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
Suzuki Ignis (MF, ab 2016) – Bekannte Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · 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
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
Suzuki Ignis : avis, qualités et défauts des propriétairesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
Suzuki Swift 2 : avis, qualités et défauts des propriétairesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
BMW i8 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026