The Vauxhall A20NHT is a 1,956 cc, inline‑four turbo‑diesel engine produced between 2017 and 2022. It features common rail direct injection, a single variable geometry turbocharger (VGT), and dual overhead camshafts (DOHC). In standard form it delivers 110 kW (150 PS) and 350 Nm of torque, with strong low‑rpm responsiveness suitable for both urban and motorway driving.
Fitted to models such as the Insignia B, Astra K, and Grandland X, including the 2.0 CDTi 150 variants,…
All production years (2017–2022) meet Euro 6d-TEMP (2017–2019) or Euro 6d (2020–2022) standards .
The Vauxhall A20NHT is a 1,956 cc inline‑four turbo‑diesel engineered for mid‑size and SUV platforms (2017–2022). It combines Bosch high-pressure common-rail injection with a variable-geometry turbocharger and AdBlue-based SCR aftertreatment to deliver responsive torque and strict emissions compliance. Designed to meet Euro 6d-TEMP and Euro 6d standards, it balances performance with regulatory adherence and real-world drivability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,956 cc | |
Fuel type | Diesel | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Turbocharged | |
Bore × stroke | 83.0 mm × 90.4 mm | |
Power output | 110 kW (150 PS) | |
Torque | 350 Nm @ 1,750–2,500 rpm | |
Fuel system | Bosch CP4.2 common‑rail (up to 2,000 bar) | |
Emissions standard | Euro 6d-TEMP (2017–2019); Euro 6d (2020–2022) | |
Compression ratio | 15.5:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Single variable‑geometry turbo (Garrett) | |
Timing system | Chain (front‑mounted) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 158 kg |
The Vauxhall A20NHT was used across Vauxhall's Insignia B, Astra K, and Grandland X platforms with transverse mounting and shared with Peugeot and Citroën under Stellantis (formerly PSA-GM) collaboration. This engine received platform-specific adaptations—revised engine mounts in the Grandland X and modified exhaust routing in the Insignia Sports Tourer—and from 2020 the Euro 6d update introduced enhanced SCR catalysts and updated AdBlue dosing logic, creating minor calibration interchange limits. 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 offers strong torque and Euro 6d compliance, but early models (2017–2018) had AdBlue crystallisation concerns. Post-2019 revisions improved dosing reliability. With regular long-distance driving, correct GM dexos2 Gen 2 oil, and EN 590 diesel, well-maintained examples can exceed 200,000 km reliably.
Top issues include AdBlue injector crystallisation from short trips, DPF ash buildup, EGR cooler leaks, and CP4.2 fuel pump wear. These are documented in Vauxhall SIB 18-074 and DVSA emissions data. Most are preventable with proper driving habits and maintenance.
The 2.0 CDTi 150 (A20NHT) powered the Insignia B (2017–2022), Astra K (2018–2021), and Grandland X (2017–2022). It was also used in Opel equivalents and shared architecture with Peugeot/Citroën 2.0 BlueHDi under the Stellantis alliance.
Aftermarket ECU tuning is common on the A-20-NHT 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.
Good for its class. In an Insignia B 2.0 CDTi 150, expect ~5.5 L/100km combined (51 mpg UK). Highway driving can achieve ~4.6 L/100km (61 mpg UK), while city use may rise to ~6.8 L/100km (42 mpg UK), depending on traffic and AdBlue system status.
Yes. The A20NHT is an interference engine. If the timing chain fails or jumps, piston-to-valve contact can cause catastrophic damage. However, the front-mounted chain is generally robust if serviced correctly with proper oil.
Vauxhall specifies GM dexos2 Gen 2 0W-30 synthetic oil. This low-SAPS formulation is critical for protecting the CP4.2 pump, turbo, and aftertreatment systems. Oil changes every 15,000 km (or annually) are essential—extended intervals risk pump, chain, and DPF damage.
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.