BMW B48 / B38 vs 1.5 EcoBoost: which engine is more reliable?

According to our risk index, the BMW B48 / B38 carries less risk than the 1.5 EcoBoost: 24/100 (low risk) versus 43/100 (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 1.5 EcoBoost has 2 documented serious faults, the main one being «Coolant loss through a microcrack in the engine block (4-cylinder 1.5)».

Risk index

BMW B48 / B38

Low risk · 1 serious fault

Lower risk

Risk index

1.5 EcoBoost

Moderate risk · 2 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 202618 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 1.5 EcoBoost reliable?

These are two engines with the same name. The four-cylinder (2014-2019: Mondeo, Focus, Kuga, C-Max) has documented cases of coolant loss through a microcrack in the block, which can end in a new engine. The three-cylinder Dragon (from 2018) has hardly any mechanical faults cited, but the Kuga has been recalled several times because an injector can crack and cause a fuel leak with a fire risk.^[4][5][6][7]

See the 2 of the 1.5 EcoBoost faults

Side-by-side comparison

Comparison of BMW B48 / B38 and 1.5 EcoBoost
Item	BMW B48 / B38	1.5 EcoBoost
Technical data
Type	Engine	Engine
Fuel	Petrol	Petrol
Displacement	1,998 cm³	1,498 cm³
Timing	Chain	Chain
Power	136–312 hp	120–200 hp
Production	since 2014^[1][8][9]	since 2014^{[10][11][12][13][14]}
Reliability
Risk index (what is it?)	24Low risk	43Moderate risk
Documented faults	4	2
Of high or critical severity	1	2
Worst severity	High severity	Critical 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	Critical severity: Coolant loss through a microcrack in the engine block (4-cylinder 1.5) Critical severity: Fuel leak from cracked injectors, with a fire risk (Kuga Dragon)
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][15] B48 2.0 up to 302-312 hp, high performance (MINI John Cooper Works, BMW X1 M35i)^[2]	None
With cautionVersions to be cautious about	None	1.5 EcoBoost 4-cylinder 120/150/160/182 hp (Mondeo, Focus, Kuga, C-Max, S-Max, Galaxy, 2014-2019)^[4][5] 1.5 EcoBoost Dragon 3-cylinder 120/150/182 hp (Kuga III and Focus IV, from 2018)^{[6][7][16][17]} 1.5 EcoBoost ST 200 hp (Fiesta ST 2018-2023 and Puma ST, code YZJA)^[6][12][18]
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

1.5 EcoBoost

See the 10 models with the 1.5 EcoBoost

Other comparisons

With the BMW B48 / B38

With the 1.5 EcoBoost

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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
Ford Mondeo V - Auto ReviewANWB · Consumer association · published 2 September 2024 · consulted 8 October 2026 · in Dutch
Ford EcoBoost Probleme und Haltbarkeitgebrauchtwagenberater.de · Motoring press · consulted 8 October 2026 · in German
Rückruf: Bei diesen Ford-Modellen besteht BrandgefahrADAC · Motoring press · published 2 February 2026 · consulted 8 October 2026 · in German
Rückruf Ford Kuga: Brandgefahr wegen defekter Einspritzventileauto motor und sport · Motoring press · published 3 May 2024 · consulted 8 October 2026 · in German
BMW B38Wikipedia (inglés) · Other source · consulted 27 September 2026
BMW B48Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Ford EcoBoost engineWikipedia (en) · Other source · consulted 8 October 2026
Ford EcoBoostWikipedia (de) · Other source · consulted 8 October 2026 · in German
Every Ford Powered By The 1.5L EcoBoost 'Dragon'SlashGear · Motoring press · consulted 8 October 2026
Ford Kuga Titanium 1.5 EcoBoost Auto-Start-Stop 150 CV 4x2 (2014-2016): precio y ficha técnicakm77 · Technical documentation · consulted 8 October 2026 · in Spanish
Ford Kuga MK3 2019-2026 Probleme und Schwachstellengebrauchtwagenberater.de · Motoring press · consulted 8 October 2026 · in German
5 BMWs That Prove the B48 Four-Cylinder Engine Is Better Than You ThinkBMWBLOG · Other source · published April 2026 · consulted 27 September 2026
Trois problèmes avec le Ford Kuga : jauge de carburant, injecteurs et toit panoramique défectueuxcar-recalls.eu · Other source · consulted 8 October 2026 · in French
Tous les problèmes sur Ford FOCUS 4 2018 (93 témoignages)fiches-auto.fr · Owners' forum · consulted 8 October 2026 · in French
YZJA engine (Ford 1.5 EcoBoost)Motorinsel · Technical documentation · consulted 8 October 2026