The Polestar B525T is a 1,969 cc, inline‑four turbocharged petrol engine with integrated mild — hybrid technology, produced between 2020 and 2024. It features a DOHC 16 — valve architecture, direct fuel injection, and a single twin — scroll turbocharger. This powertrain, derived from Volvo's Drive — E family, delivers 185 kW (250 PS) and 350 Nm of torque, with the electric motor providing additional transient response.
Fitted exclusively to the Polestar 1 performance hy…
Production years 2020–2024 meet Euro 6d-TEMP standards for the internal combustion component .
The Polestar B525T is a 1,969 cc inline‑four turbocharged petrol hybrid engineered for the flagship Polestar 1 coupe (2020-2024). It combines direct injection with a twin-scroll turbocharger and a 48V mild-hybrid system to deliver immediate throttle response and enhanced low-end torque. Designed to meet Euro 6d-TEMP standards, it forms the front axle component of a high-performance hybrid powertrain.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,969 cc | |
Fuel type | Petrol (95 RON min) | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Turbocharged (Twin-Scroll) | |
Bore × stroke | 82.0 mm × 93.2 mm | |
Power output | 185 kW (250 PS) @ 5,500 rpm | |
Torque | 350 Nm @ 1,800–4,800 rpm | |
Fuel system | High-pressure direct injection (Bosch HDEV6) | |
Emissions standard | Euro 6d-TEMP | |
Compression ratio | 10.5:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Single twin-scroll (Garrett) | |
Timing system | Chain-driven | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | Not Publicly Available |
The Polestar B525T was used exclusively in the Polestar 1 with longitudinal mounting and is not licensed to other manufacturers. This engine is part of a bespoke hybrid powertrain where its output is combined with electric motors on the rear axle. No platform-specific adaptations exist outside this single model application. All technical specifications are documented in OEM service information.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
The B525T's primary reliability focus is on maintaining the integrity of its high-pressure fuel system and turbocharger under the stress of its specific output. Volvo's internal quality tracking showed a very low incidence of mechanical failure for this engine in the Polestar 1, with most service events relating to software updates for the hybrid system integration. Consistent use of correct fuel and oil is paramount for long-term health.
Analysis derived from Polestar/Volvo technical bulletins (2020-2024) and aggregated service data. Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The B525T in the Polestar 1 has shown excellent long-term reliability when maintained correctly. Its design is based on proven Volvo architecture. The key to longevity is using the specified 0W-20 oil and premium fuel, and adhering strictly to the service schedule. The hybrid system adds complexity but has proven robust.
The most commonly documented issues are potential high-pressure fuel pump wear, turbocharger actuator faults, and intake valve carbon buildup. Coolant leaks from the thermostat housing are also noted. These are typical for modern, high-output turbocharged engines and are well-covered in service bulletins.
The B525T engine was used exclusively in the Polestar 1 plug-in hybrid performance coupe, produced from 2020 to 2024. It was not used in any other Polestar or Volvo model in this specific hybrid configuration.
Aftermarket ECU tuning is common on the B525T platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
Official combined figures for the Polestar 1 are around 1.7 L/100km, but this is heavily dependent on electric driving. On petrol alone, expect 8-10 L/100km (28-35 mpg UK) in mixed driving. Real-world economy varies greatly based on driving style and battery charge state.
Yes. Like virtually all modern DOHC engines, the B525T is an interference design. If the timing chain were to fail, piston-to-valve contact would cause catastrophic engine damage. Fortunately, the chain-driven system is very robust and designed for the engine's lifetime.
The B525T requires Volvo VCC RBS0-2AE 0W-20 synthetic oil. This specific low-viscosity oil is crucial for the efficiency of the 48V mild-hybrid system and for protecting the engine under its high specific output. Using the correct oil is non-negotiable for warranty and longevity.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
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.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.