Skip to content
MotorFiable
en

BMW B48 / B38 vs BMW B58: which engine is more reliable?

According to our risk index, the BMW B48 / B38 carries less risk than the BMW B58: 24/100 (low risk) versus 38/100 (moderate 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 BMW B58 has 1 documented serious fault, the main one being «Failure of the oil pump with a plastic rotor housing».

Risk index

BMW B48 / B38

24

Low risk · 1 serious fault

Lower risk

Risk index

BMW B58

38

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

13 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 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.[4][5][6][7]

See the 6 of the BMW B58 faults

Side-by-side comparison

Comparison of BMW B48 / B38 and BMW B58
BMW B48 / B38BMW B58
Technical data
TypeEngineEngine
FuelPetrolPetrol
Displacement1,998 cm³2,998 cm³
TimingChainChain
Power136–312 hp290–441 hp
Productionsince 2014[1][8][9]since 2015[10][11]
Reliability
Risk index (what is it?)24Low risk38Moderate risk
Documented faults46
Of high or critical severity11
Worst severityHigh severityHigh 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. High severity: Failure of the oil pump with a plastic rotor housing
  2. Medium severity: Oil and coolant leak from the plastic oil filter housing
  3. Medium severity: Failure of the crankcase ventilation PCV valve (integrated in the valve cover)
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][12]
  • B48 2.0 up to 302-312 hp, high performance (MINI John Cooper Works, BMW X1 M35i)[2]
  • B58TU2 381 hp (B58B30M2, since 2022)[5][6]
With cautionVersions to be cautious aboutNone
  • B58 326 hp (B58B30M0, 2015-2019)[5][6][13]
  • B58 340-360 hp (B58B30M0, 2016-2019)[5][6][13]
  • B58TU 333-340 hp (B58B30M1, since 2018)[5][6]
  • B58TU 374 hp (B58B30O1, M340i, M440i and M240i, since 2019)[6]
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

BMW B58

See the 15 models with the BMW B58

Other comparisons

With the BMW B48 / B38

With the BMW B58

Compare other engines

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.

  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. The 5 Most Common BMW B58 Engine ProblemsBMW Tuning · Technical documentation · published 7 February 2020 · consulted 9 October 2026
  5. BMW B58 EngineFCP Euro · Technical documentation · consulted 9 October 2026
  6. The Popular BMW B58 Inline-Six Engine Has One Big Achilles HeelThe Autopian · Motoring press · published 14 June 2024 · consulted 9 October 2026
  7. ¿En qué se diferencian los motores B58 y S58 de BMW?Diariomotor · Motoring press · published 27 April 2024 · consulted 9 October 2026 · in Spanish
  8. BMW B38Wikipedia (inglés) · Other source · consulted 27 September 2026
  9. BMW B48Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  10. BMW B58Wikipedia (inglés) · Other source · consulted 9 October 2026
  11. BMW B58Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
  12. 5 BMWs That Prove the B48 Four-Cylinder Engine Is Better Than You ThinkBMWBLOG · Other source · published April 2026 · consulted 27 September 2026
  13. 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