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BMW B48 / B38 vs 1.0 and 1.4 Boosterjet: which engine is more reliable?

According to our risk index, the 1.0 and 1.4 Boosterjet carries less risk than the BMW B48 / B38: 6/100 versus 24/100 (both low risk). The BMW B48 / B38 has 1 documented serious fault, the main one being «Timing chain on the early units (2014-2018), redesigned in the B48TU»; the 1.0 and 1.4 Boosterjet has no documented serious faults.

Risk index

BMW B48 / B38

24

Low risk · 1 serious fault

Risk index

1.0 and 1.4 Boosterjet

6

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

17 sourcesHow we work

Is the BMW B48 / B38 reliable?

The BMW B48 (2.0 turbo, from 2014) and its three-cylinder sibling, the B38 (1.5), have a reputation as reliable engines within BMW's modern range: there is no serious, widespread fault on record, unlike the timing chain on the N47 diesel or the EGR fire risk on the B47. Keep an eye on the cooling circuit, the oil seals near the turbo and the VANOS, and the carbon build-up typical of direct injection; BMW revised the timing chain in 2018 (B48TU update).[1][2][3]

See the 4 of the BMW B48 / B38 faults

Is the 1.0 and 1.4 Boosterjet reliable?

The Suzuki Boosterjet (1.0 K10C and 1.4 K14C/K14D) is a turbocharged direct-injection petrol engine with a timing chain, fitted since 2015 to the Vitara, S-Cross, Swift Sport and Baleno, with a 48 V mild-hybrid variant of the 1.4 since 2020. German TÜV inspection reports and the workshops we consulted rate its reliability as high: no widespread fault with the chain, oil, fuel pump or mild-hybrid system is documented.[4][5][6][7][8]

See the 4 of the 1.0 and 1.4 Boosterjet faults

Side-by-side comparison

Comparison of BMW B48 / B38 and 1.0 and 1.4 Boosterjet
BMW B48 / B381.0 and 1.4 Boosterjet
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement1,998 cm³—
TimingChainChain
Power136–312 hp110–140 hp
Productionsince 2014[1][9][10]since 2015[4][11][12][13]
Reliability
Risk index (what is it?)24Low risk6Low risk
Documented faults44
Of high or critical severity10
Worst severityHigh severityLow severity
Main faults
  1. Medium severity: Deterioration of hoses and seals in the cooling circuit, with coolant loss
  2. Medium severity: Oil leaks or seepage from seals and covers, near the turbo and the VANOS
  3. High severity: Timing chain on the early units (2014-2018), redesigned in the B48TU
  1. Low severity: Timing chain: no documented pattern of failures
  2. Low severity: Oil consumption: no documented pattern
  3. Low severity: Direct injection and fuel pump: no documented faults or recalls
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versions
  • B38 1.5 136 hp (MINI Cooper, 118i)[2]
  • B48 2.0 178-197 hp (120i, 220i, 320i, 520i, X1/X2/X3 20i, MINI Cooper S)[2]
  • B48 2.0 252-258 hp (330i, 530i, X3/X4 xDrive30i)[2][14]
  • B48 2.0 up to 302-312 hp, high performance (MINI John Cooper Works, BMW X1 M35i)[2]
  • 1.0 Boosterjet 110-112 hp (K10C, three-cylinder, 2015-present)[5][6][15][16]
  • 1.4 Boosterjet 140 hp (K14C, non-hybrid, 2015-2020 in Europe)[5][6][17]
  • 1.4 Boosterjet Mild Hybrid 129 hp (K14D, 48V SHVS, since 2020)[12][13]
With cautionVersions to be cautious aboutNoneNone
AvoidVersions to avoidNoneNone

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 B48 / B38

See the 17 models with the BMW B48 / B38

1.0 and 1.4 Boosterjet

See the 12 models with the 1.0 and 1.4 Boosterjet

Other comparisons

With the BMW B48 / B38

With the 1.0 and 1.4 Boosterjet

Compare other engines

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Sources

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

  1. BMW B48Wikipedia (inglés) · Other source · consulted 27 September 2026
  2. Motor BMW B48: defectos, mantenimiento y guía de compraRecambios y Accesorios BMW (blog) · Technical documentation · consulted 27 September 2026 · in Spanish
  3. BMW Reliability Has Changed, But the Internet Hasn't Caught UpBMWBLOG · Other source · published January 2026 · consulted 27 September 2026
  4. Suzuki K engineWikipedia · Other source · consulted 27 September 2026
  5. Gebrauchtwagen-Check: Grundsätzlich gut: Der Suzuki Vitara beim TÜVVolksstimme (dpa) · General press · published January 2026 · consulted 27 September 2026 · in German
  6. Suzuki Swift als Gebrauchtwagen: Diese Punkte beanstandet der TÜV häufigT-Online · General press · published October 2025 · consulted 27 September 2026 · in German
  7. Los mecánicos recomiendan el Suzuki Vitara porque no presume de moderno, sino de sencillo y baratoEl Nacional · General press · published September 2026 · consulted 27 September 2026 · in Spanish
  8. Test complet Suzuki VitaraFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  9. BMW B38Wikipedia (inglés) · Other source · consulted 27 September 2026
  10. BMW B48Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  11. Suzuki motor KWikipedia · Other source · consulted 27 September 2026 · in Spanish
  12. Suzuki Swift Sport, Vitara y S-Cross: nuevas versiones micro-híbridas de 48VAutopista.es · Motoring press · published 16 December 2019 · consulted 27 September 2026 · in Spanish
  13. Suzuki S-Cross 1.4 Boosterjet Mild Hybrid 2020: precios y datos del nuevo SUVAutopista.es · Motoring press · published 12 March 2020 · consulted 27 September 2026 · in Spanish
  14. 5 BMWs That Prove the B48 Four-Cylinder Engine Is Better Than You ThinkBMWBLOG · Other source · published April 2026 · consulted 27 September 2026
  15. Suzuki Vitara : avis, qualités et défauts des propriétairesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  16. Suzuki Swift 3 : avis, qualités et défauts des propriétairesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  17. Prueba Suzuki Swift Sport 1.4 Boosterjet 140 CVActualidad Motor · Motoring press · published 16 May 2018 · consulted 27 September 2026 · in Spanish