BMW B48 / B38 vs Skyactiv-G: which engine is more reliable?

According to our risk index, the BMW B48 / B38 carries less risk than the Skyactiv-G: 24/100 (low risk) versus 25/100 (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 Skyactiv-G has no documented serious faults.

Risk index

BMW B48 / B38

Low risk · 1 serious fault

Lower risk

Risk index

Skyactiv-G

Moderate 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 27 September 202613 sources How 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 Skyactiv-G reliable?

The Skyactiv-G is a naturally aspirated petrol engine that the German specialist press consistently describes as reliable, with no documented pattern of serious engine faults in any Mazda model reviewed. Its weak point, shared with almost any direct-injection petrol engine, is carbon build-up in the intake; in addition, 2017-2020 units had recalls for software and for the fuel pump, since fixed by the manufacturer.^[4][5][6][7]

See the 5 of the Skyactiv-G faults

Side-by-side comparison

Comparison of BMW B48 / B38 and Skyactiv-G
Item	BMW B48 / B38	Skyactiv-G
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	1,998 cm³	—
Timing	Chain	Chain
Power	136–312 hp	75–187 hp
Production	since 2014^[1][8][9]	since 2011^[4][10]
Reliability
Risk index (what is it?)	24Low risk	25Moderate risk
Documented faults	4	5
Of high or critical severity	1	0
Worst severity	High severity	Medium severity
Main faults	Medium severity: Deterioration of hoses and seals in the cooling circuit, with coolant loss Medium severity: Oil leaks or seepage from seals and covers, near the turbo and the VANOS High severity: Timing chain on the early units (2014-2018), redesigned in the B48TU	Medium severity: Intake shut-off valve software issue and engine stalling Medium severity: Micro-cracks in the fuel pump impeller Medium severity: ECU programming and loss of power (CX-5 II and Mazda3 IV)
Most expensive documented repair	No reliable data	No 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][11] B48 2.0 up to 302-312 hp, high performance (MINI John Cooper Works, BMW X1 M35i)^[2]	1.5 Skyactiv-G (P5-VPS)^[5][12] 2.0 Skyactiv-G (PE-VPS)^[6][7][13] 2.5 Skyactiv-G (PY-VPS)^[6]
With cautionVersions to be cautious about	None	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 B48 / B38

See the 20 models with the BMW B48 / B38

Skyactiv-G

See the 9 models with the Skyactiv-G

Other comparisons

With the BMW B48 / B38

With the Skyactiv-G

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 B48Wikipedia (inglés) · Other source · consulted 27 September 2026
Motor BMW B48: defectos, mantenimiento y guía de compraRecambios y Accesorios BMW (blog) · Technical documentation · consulted 27 September 2026 · in Spanish
BMW Reliability Has Changed, But the Internet Hasn't Caught UpBMWBLOG · Other source · published January 2026 · consulted 27 September 2026
SkyactivWikipedia (inglés) · Other source · consulted 27 September 2026
Mazda 3 (BM/BN, 2013-2019) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda 6 (GJ, III) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda CX-5 II (KF) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
BMW B38Wikipedia (inglés) · Other source · consulted 27 September 2026
BMW B48Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
List of Mazda enginesWikipedia (inglés) · Other source · consulted 27 September 2026
5 BMWs That Prove the B48 Four-Cylinder Engine Is Better Than You ThinkBMWBLOG · Other source · published April 2026 · consulted 27 September 2026
Mazda 2 (DJ) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
Mazda 3 IV (BP) – Erfahrungen & ProblemeGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German