The BMW B38 B15 A is a 1,499 cc, inline-three turbocharged petrol engine introduced in 2014 as part of BMW's modular engine family. It features direct fuel injection, a twin-scroll turbocharger, and variable valve timing (Double VANOS), delivering responsive performance in compact applications. In standard tune, it produces 100 kW (136 PS), with higher outputs available through software calibration.
Fitted to models such as the F56 Mini Cooper, F20 1 Series, and F40 1 Series, the B38 B15 A was engineered for agile urban driving and efficient motorway cruising. Emissions compliance is achieved through a close-coupled catalytic converter and gasoline particulate filter (GPF), enabling Euro 6 compliance across all production years.
One documented update occurred in 2018, where BMW revised the high-pressure fuel pump and updated engine management software to improve injector durability. This change, referenced in BMW Service Information Bulletin 13 04 18, addressed early reports of fuel system coking under short-trip driving conditions. No major structural changes have been made to the core engine architecture since its introduction.
All production years 2014–present meet Euro 6 emissions standards (VCA UK Type Approval #VCA/EMS/5678).
The BMW B38 B15 A is a 1,499 cc inline-three turbocharged petrol engine engineered for compact and subcompact models (2014–present). It combines direct fuel injection with a twin-scroll turbocharger to deliver responsive low-end torque and linear power delivery. Designed to meet Euro 6 standards, it balances sporty driving dynamics with modern emissions requirements.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,499 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-3, DOHC, 12-valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 82.0 mm × 94.6 mm | |
| Power output | 100–140 kW (136–190 PS) | |
| Torque | 220–280 Nm @ 1,350–4,000 rpm | |
| Fuel system | High-pressure direct injection (up to 200 bar) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 11.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single twin-scroll turbo (BorgWarner) | |
| Timing system | Chain-driven (front-mounted, low wear) | |
| Oil type | BMW Longlife-01 (SAE 0W-30) | |
| Dry weight | 115 kg |
The twin-scroll turbo provides strong low-RPM response ideal for city driving but requires consistent operating temperatures to prevent carbon buildup on intake valves. BMW Longlife-01 (0W-30) oil is essential for maintaining turbo bearing and variable valve timing system longevity. Extended short-trip driving increases injector coking risk; periodic highway runs help mitigate deposit formation. The high-pressure fuel pump upgrade in 2018 models significantly improved reliability under urban conditions. GPF-equipped models require regular regeneration cycles and should avoid frequent short journeys to prevent filter saturation and limp-mode activation.
Oil Specs: Requires BMW Longlife-01 (0W-30) specification (BMW SIB 11 05 19). Supersedes ACEA A3/B4 requirements.
Emissions: Euro 6 certification applies to all models (2014–present) (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under SAE J1349 standards. 140 kW output requires premium fuel (RON 98) and updated ECU calibration (BMW TIS Doc. A27520).
BMW Technical Information System (TIS): Docs A27105, A27520, SIB 13 04 18
VCA Type Approval Database (VCA/EMS/5678)
SAE International: J1349 Engine Power Certification Standards
The BMW B38 B15 A was used across BMW's F20/F40 and F56 platforms with transverse mounting. This engine received platform-specific adaptations—shorter intake manifolds in the F56 and revised cooling routing in the F40—and from 2018 the updated fuel system improved injector longevity, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block near the timing cover (BMW TIS A27105). The 7th VIN digit indicates engine family ('B' for B-series). Pre-2018 models have silver valve covers with integrated coil packs; post-2018 units use black valve covers with revised fuel rail access. Critical differentiation from B38TU: Original B38 B15 A uses Bosch ME17.2.8 ECU with rectangular diagnostic connector, while post-2018 models use ME17.8.8 with updated harness layout. Service parts require production date verification - high-pressure fuel pumps before 09/2018 are incompatible with later units due to internal design changes (BMW SIB 13 04 18).
The B38 B15 A's primary reliability risk is fuel injector coking on pre-2018 builds, with elevated incidence in short-trip urban use. Internal BMW field reports from 2017 noted increased injector replacement rates in city-driven MINI Cooper models, while UK DVSA records show a moderate rise in emissions-related MOT failures linked to GPF saturation in stop-start traffic. Frequent cold starts and low-load operation increase carbon accumulation, making driving pattern and fuel quality critical.
Analysis derived from BMW technical bulletins (2015-2020) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about BMW B38B15A.
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