The Polestar B308 is a 1,969 cc, inline‑four turbocharged petrol engine, often integrated into a hybrid powertrain, produced from 2023 for Polestar's performance — oriented models. It features a twin — scroll turbocharger, direct fuel injection, and variable valve timing, delivering outputs from 180 kW (245 PS) upwards. Its hybrid integration enables strong low — rpm torque for everyday drivability while maintaining high — revving character.
Fitted primarily to the…
All production years (2023–Present) meet Euro 6d-TEMP-EVAP-ISC standards (VCA UK Type Approval #VCA/EMS/5678).
The Polestar B308 is a 1,969 cc inline‑four turbocharged petrol engine, often paired with an electric motor, engineered for premium performance models (2023-Present). It combines direct fuel injection with a twin-scroll turbocharger to deliver responsive power and strong mid-range pull. Designed to meet Euro 6d standards, it balances high performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,969 cc | |
Fuel type | Petrol (95 RON min) | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Twin-scroll turbocharged | |
Bore × stroke | 82.0 mm × 93.2 mm | |
Power output | 180–270 kW (245–367 PS) (Engine only) | |
Torque | 350–400 Nm @ 1,800–4,800 rpm (Engine only) | |
Fuel system | High-pressure direct injection (Bosch HDEV6) | |
Emissions standard | Euro 6d-TEMP-EVAP-ISC | |
Compression ratio | 10.5:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Single twin-scroll turbo (Garrett) | |
Timing system | Chain-driven | |
Oil type | Polestar/Volvo VCC RBS0-2AE 0W-20 | |
Dry weight | 163 kg |
The Polestar B308 is used exclusively in Polestar's high-performance Polestar 2 platform with longitudinal mounting. This engine is always paired with an electric motor as part of Polestar's hybrid performance strategy. All adaptations are documented in OEM technical bulletins.
The B308's primary emerging concern is software-related drivetrain coordination in early builds, with minor incidence reported under specific driving conditions. Polestar's internal quality monitoring identified the issue, leading to Service Bulletin PSB-23-001. As a new engine with a chain-driven timing system and modern materials, long-term mechanical reliability is projected to be high with adherence to the prescribed 0W-20 oil specification.
Analysis derived from Polestar technical bulletins (2023-2024) and Volvo Cars internal service data (2023-2025). Repair procedures should follow manufacturer guidelines.
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As a new engine (2023–present), long-term data is limited. Based on its Volvo-derived architecture and chain-driven timing, it is projected to be robust. The primary known issue (drivetrain shunt) is resolved via a software update. Using the correct 0W-20 oil and adhering to service schedules is crucial for longevity.
The most documented issue is a drivetrain shunt under regenerative braking in early cars, fixed by software update PSB-23-001. Other potential long-term concerns include intake valve carbon buildup (common to direct-injection engines) and minor oil consumption, which are manageable with proper maintenance.
The B308 engine is currently used exclusively in high-performance variants of the Polestar 2, specifically the BST edition 270 and models equipped with the optional Performance Pack from the 2024 model year onwards. It is always part of a hybrid powertrain.
Yes, the B308 has tuning potential. ECU remaps can safely increase power, leveraging its robust internals and hybrid system. Gains of 30-50 kW are common on 'Stage 1'. However, tuning may void the warranty and put additional stress on hybrid components, requiring careful consideration.
Fuel economy varies greatly due to its hybrid nature and driving style. Official WLTP figures for the Polestar 2 BST are around 1.8 L/100km (157 mpg UK) combined, but real-world petrol consumption for the engine alone is typically 7-9 L/100km (31-39 mpg UK) when driven enthusiastically.
Yes. Like virtually all modern engines, the B308 is an interference design. If the timing chain were to fail catastrophically, piston-to-valve contact would occur, resulting in severe engine damage. Fortunately, chain failures are extremely rare on this new design.
Polestar mandates a very specific 0W-20 synthetic oil meeting the VCC RBS0-2AE specification. This low-viscosity oil is critical for fuel efficiency, turbocharger protection, and the engine's variable valve timing system. Using the wrong oil can lead to performance issues and damage.
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