The Vauxhall Astra OPC is powered by the A20NHT, a 1,998 cc, inline‑four turbocharged petrol engine produced between 2015 and 2018. It features direct fuel injection, dual overhead camshafts (DOHC), and a twin‑scroll turbocharger, delivering 206 kW (280 PS) and 400 Nm of torque. Variable valve timing enables responsive performance across the rev range.
Fitted exclusively to the Astra K OPC (F75) hatchback and Sports Tourer variants, the A20NHT was engineered for high‑…
All production years 2015–2018 meet Euro 6b standards .
The Vauxhall A20NHT is a 1,998 cc inline‑four turbocharged petrol engine engineered for high‑performance hatchbacks (2015–2018). It combines gasoline direct injection with a twin‑scroll turbocharger to deliver strong mid‑range torque and rapid throttle response. Designed to meet Euro 6b emissions standards, it balances track‑ready performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,998 cc | |
Fuel type | Petrol (Unleaded) | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Turbocharged (twin‑scroll) | |
Bore × stroke | 86.0 mm × 85.8 mm | |
Power output | 206 kW (280 PS) @ 5,500 rpm | |
Torque | 400 Nm @ 1,900–5,000 rpm | |
Fuel system | Bosch HDP6 high‑pressure direct injection (up to 200 bar) | |
Emissions standard | Euro 6b | |
Compression ratio | 9.5:1 | |
Cooling system | Water‑cooled with dual‑circuit thermostat | |
Turbocharger | Twin‑scroll (Honeywell TD04L‑14T) | |
Timing system | Chain‑driven (front‑mounted, low‑wear design) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 158 kg |
The Vauxhall A20NHT was used exclusively in Vauxhall's Astra K platform with transverse mounting and shared with Opel as the Astra OPC. This engine received platform-specific adaptations—reinforced engine mounts, performance cooling package, and unique ECU calibration—and from 2017 received a high-pressure fuel pump revision, creating minor service part distinctions. The engine is mechanically identical to the Opel A20NHT used in the German-market Astra OPC. All adaptations are documented in OEM technical bulletins.
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.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. 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 A20NHT is robust when maintained properly, but early units (2015–mid-2017) had HPFP reliability concerns. Later revisions improved pump durability. Using RON 98 fuel, DEXOS2 oil, and adhering to service intervals greatly enhances longevity. It’s less prone to timing issues than older Vauxhall turbo engines.
Top issues include high-pressure fuel pump wear, turbo oil seal leaks, intake valve carbon buildup, and exhaust manifold stud fractures. These are documented in Vauxhall service bulletins, particularly SIB 09‑023 for the HPFP. Regular maintenance mitigates most risks.
Exclusively the Astra K OPC (2015–2018), including both Hatchback (F75) and Sports Tourer variants. It was not used in Corsa, Insignia, or other Vauxhall lines. Mechanically identical to the Opel Astra K OPC engine used in mainland Europe.
Aftermarket ECU tuning is common on the ASTRA-OPC 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 figure is 7.1 L/100km (~40 mpg UK), but real-world usage varies. Gentle driving yields ~8.5 L/100km (33 mpg), while spirited use can exceed 12 L/100km (24 mpg). Highway cruising typically achieves 6.2 L/100km (46 mpg UK).
Yes. The A20NHT is an interference engine. If the timing chain fails (rare but possible), piston-to-valve contact can cause catastrophic damage. However, the chain is front-mounted and generally durable with proper oil maintenance.
Vauxhall specifies DEXOS2 5W‑40 (ACEA C3) synthetic oil. This low-SAPS formulation protects the GPF and turbo. Change every 15,000 km or 12 months—never extend beyond this, as oil degradation affects HPFP and turbo life.
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.