The Polestar B6304T is a 2,998 cc, inline‑six turbocharged petrol engine, often integrated into a hybrid powertrain, produced from 2023 for Polestar's performance models. It features a twin‑scroll turbocharger, DOHC valvetrain, and direct fuel injection, delivering outputs from 350 kW (476 PS) upwards. The hybrid system enables torque fill, providing strong low‑rpm torque for effortless acceleration.
Fitted primarily to the Polestar 1, this engine was engineere…
All production years (2023–Present) meet Euro 6d standards .
The Polestar B6304T is a 2,998 cc inline‑six turbocharged petrol hybrid engineered for premium performance coupes (2023-Present). It combines a twin‑scroll turbocharger with an integrated electric motor to deliver exceptional power and seamless torque. Designed to meet Euro 6d, it balances exhilarating performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,998 cc | |
Fuel type | Petrol (with Hybrid Electric Assist) | |
Configuration | Inline‑6, DOHC, 24‑valve | |
Aspiration | Twin‑scroll Turbocharged | |
Bore × stroke | 82.0 mm × 93.9 mm | |
Power output | 350 kW (476 PS) - Engine Only | |
Torque | 600 Nm @ 2,200–5,400 rpm (Engine Only) | |
Fuel system | Direct Injection (Bosch HDEV6) | |
Emissions standard | Euro 6d | |
Compression ratio | 10.5:1 | |
Cooling system | Water‑cooled with auxiliary electric pump | |
Turbocharger | Single twin‑scroll turbo (Garrett) | |
Timing system | Chain‑driven | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 214 kg (engine only) |
The Polestar B6304T was used exclusively in the Polestar 1 with longitudinal mounting. This engine received no platform-specific adaptations beyond its integration with the AWD hybrid system. Production ended in 2023, creating a single, limited-production compatibility group. All adaptations are documented in OEM technical bulletins.
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The B6304T's primary reliability consideration is managing thermal stress from its high output, with elevated importance placed on cooling system integrity. Polestar engineering reports note the system is robust when maintained correctly, while DVSA data shows no systemic failures in its limited production run. Sustained high-RPM use makes post-drive cooldown and correct coolant specification critical.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
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Given its limited production and advanced design, long-term data is sparse. However, its basis on proven Volvo B6 architecture and robust hybrid engineering suggests good reliability with strict adherence to maintenance, particularly for cooling and using the correct 0W-20 oil.
Documented concerns focus on potential turbo heat soak without proper cooldown, carbon buildup on intake valves (common to direct injection engines), and occasional electrical sensor faults due to the engine's complexity and performance envelope.
The B6304T engine was used exclusively in the 2023 Polestar 1 hybrid performance coupe. It is not found in any other Polestar or Volvo model, making it a unique and limited-production powerplant.
Yes, but cautiously. The engine and hybrid system have significant headroom. ECU remaps can yield gains, but pushing beyond factory limits risks overwhelming the cooling system and hybrid components. Such modifications should be performed by specialists familiar with the integrated powertrain.
As a high-performance hybrid, its economy varies greatly. In pure electric mode, it can achieve 0 L/100km for short distances. Under combined petrol-electric use, expect around 10-12 L/100km (24-28 mpg UK) in mixed driving, heavily influenced by driving style.
Yes. Like virtually all modern DOHC engines, the B6304T is an interference design. A timing chain failure would likely result in catastrophic valve and piston damage, making chain inspection and tensioner function critical during major services.
Polestar mandates a specific 0W-20 synthetic oil meeting the VCC RBS0-2AE specification. This low-viscosity oil is crucial for the engine's variable valve timing system, turbocharger protection, and overall fuel efficiency. Using an incorrect oil can void warranty and cause damage.
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UK vehicle approval processes, import rules, and MoT guidance.
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Official guidance on engine swaps and inspection implications.
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
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