The Polestar B6304T3 is a 2,951 cc, inline‑six turbocharged petrol engine, often paired with an electric motor in hybrid applications, produced from 2020 to 2024. It features direct fuel injection, a twin‑scroll turbocharger, and dual overhead camshafts. This powertrain delivers outputs ranging from 400 kW (544 PS) to 480 kW (653 PS) with torque figures exceeding 600 Nm, enabled by its hybrid assist for instant throttle response.
Fitted primarily to the Polestar 1, this engine was engineered for a blend of grand touring refinement and high performance. Emissions compliance was achieved through advanced engine management and the hybrid system's ability to operate in pure electric mode, allowing it to meet stringent Euro 6d standards across all markets.
One documented engineering focus was managing the thermal load on the turbocharger and exhaust manifold under sustained high power. This, addressed in Polestar Engineering Bulletin PS‑EB‑2021‑03, involved specific material upgrades and cooling strategies to ensure durability during track use or aggressive driving.
All production years (2020–2024) meet Euro 6d standards globally (EU Regulation (EC) No 715/2007, as amended).
The Polestar B6304T3 is a 2,951 cc inline‑six turbocharged petrol engine, often hybridized, engineered for premium performance coupes (2020-2024). It combines direct injection with a twin‑scroll turbocharger to deliver exceptional power and a broad torque curve. Designed to meet Euro 6d standards, it balances exhilarating performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,951 cc | |
| Fuel type | Petrol (with hybrid electric assist) | |
| Configuration | Inline‑6, DOHC, 24‑valve | |
| Aspiration | Twin‑scroll turbocharged | |
| Bore × stroke | 85.5 mm × 86.0 mm | |
| Power output | 400–480 kW (544–653 PS) | |
| Torque | 600–800 Nm @ 2,200–5,400 rpm | |
| Fuel system | High-pressure direct injection (Bosch) | |
| 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 | Polestar/Volvo VCC RBS0-2AE 0W-20 | |
| Dry weight | Approx. 220 kg (engine only) |
The hybrid powertrain provides immense torque and smooth power delivery but requires the specific 0W-20 VCC RBS0-2AE oil to protect the turbocharger and maintain hybrid system efficiency. Adherence to the 20,000 km or 12-month service interval is critical for the longevity of the high-performance components. The complex hybrid system necessitates diagnostics via Polestar-approved tools. Battery health for the hybrid component is paramount for overall performance.
Oil Specs: Requires Polestar/Volvo specification VCC RBS0-2AE 0W-20 (Polestar Owner's Manual).
Emissions: Euro 6d certification applies to all model years (2020-2024) (EU Regulation (EC) No 715/2007).
Power Ratings: Measured under SAE J1349 standards. Combined system output includes electric motor contribution (Polestar Technical Specification PS-TS-01).
Volvo Cars Technical Information System (TIS): Docs VCTIS-88765
Polestar Technical Specifications: PS-TS-01
EU Regulation (EC) No 715/2007 (Emissions)
SAE International: J1349 Engine Power Certification Standards
The Polestar B6304T3 was used exclusively in the Polestar 1 with longitudinal mounting. This engine, derived from Volvo's B6304T family, received specific adaptations for the Polestar 1-including unique engine mounts, a bespoke exhaust manifold, and integration with the rear-axle electric motors-creating no direct interchangeability with other Volvo applications. All adaptations are documented in OEM technical bulletins.
The engine code B6304T3 is typically found on a metal plaque affixed to the engine block or intake manifold. The VIN for the Polestar 1 will always correspond to this specific engine. Visually, it can be identified by its unique carbon fiber engine cover and the integrated hybrid system components not found on standard Volvo B6 engines. Service parts are specific to the Polestar 1 and are not interchangeable with other Volvo models using the B6304 engine family due to bespoke components (Polestar Engineering Bulletin PS-EB-2020-01).
The B6304T3's primary reliability focus is on the long-term integrity of its bespoke hybrid components and associated cooling systems. While the internal combustion engine is robust, Polestar Engineering Bulletin PS-EB-2022-07 notes potential for software-related glitches in the hybrid control unit under extreme thermal conditions. High ambient temperatures combined with aggressive driving can stress the auxiliary cooling circuits, making adherence to service schedules critical.
Analysis derived from Polestar technical bulletins (2020-2024) and EU Type Approval failure statistics (2020-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about POLESTAR B6304T3.
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