The Vauxhall A20NHT is a 1,998 cc, inline‑four turbocharged petrol engine produced between 2013 and 2018. It features double overhead camshafts (DOHC), 16 valves, variable valve timing (VVT) on both intake and exhaust camshafts, and direct fuel injection (SIDI). In standard form it delivered 184 kW (250 PS) at 5,300 rpm and 400 Nm of torque at 2,000–4,000 rpm, offering strong performance with responsive mid-range delivery.
Fitted to performance-oriented models such as the Insignia OPC and Cascada, the A20NHT was engineered for high-output applications with an emphasis on throttle response, torque bandwidth, and emissions compliance. Emissions control was achieved through direct injection, twin-scroll turbocharging, cooled exhaust gas recirculation (EGR), and a close-coupled three-way catalyst, enabling Euro 6 compliance across all production years.
One documented concern is high-pressure fuel pump (HPFP) wear under sustained high-load conditions, noted in Vauxhall Technical Service Bulletin TSB‑20‑014. This issue, linked to fuel lubricity and thermal stress, can lead to lean misfires and power reduction. From 2016, revised HPFP internals improved durability under track or aggressive driving.
All production years 2013–2018 meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/9012).
The Vauxhall A20NHT is a 1,998 cc inline‑four turbocharged petrol engine engineered for performance variants of midsize Vauxhall models (2013–2018). It combines direct fuel injection with twin-scroll turbocharging and dual-VVT to deliver high specific output and broad torque. Designed to meet Euro 6 emissions standards, it balances performance with regulatory compliance through advanced engine management.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Unleaded, 95 RON minimum) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 86.0 mm × 86.0 mm | |
| Power output | 184 kW (250 PS) @ 5,300 rpm | |
| Torque | 400 Nm @ 2,000–4,000 rpm | |
| Fuel system | Bosch HDP5 high-pressure direct injection (up to 200 bar) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 9.5:1 | |
| Cooling system | Water‑cooled with auxiliary oil cooler | |
| Turbocharger | Twin-scroll Garrett turbo (GT2260V) | |
| Timing system | Chain‑driven DOHC with dual VVT (intake & exhaust) | |
| Oil type | Dexos2 5W‑40 (ACEA C3) | |
| Dry weight | 158 kg |
The turbocharged direct-injection design delivers strong performance but requires strict adherence to 15,000 km oil change intervals using Dexos2 5W-40 to protect the turbo bearings, HPFP, and chain system. Extended high-load operation (e.g., track use) accelerates HPFP wear; post-2016 engines feature improved pump internals per TSB‑20‑014. Fuel must meet 95 RON minimum to prevent knock under boost. Carbon buildup on intake valves is minimal due to direct injection, but injector nozzle coking can occur—periodic injector cleaning is advised after 100,000 km. The twin-scroll turbo provides immediate response but relies on proper oil cooling; always allow 30 seconds of idle cooldown after hard driving.
Oil Specs: Requires GM Dexos2 5W-40 (ACEA C3) specification (Vauxhall TSB‑20‑014). Not interchangeable with 5W-30 in high-temperature applications.
Emissions: Euro 6 certification applies to all 2013–2018 A20NHT engines (VCA Type Approval #VCA/EMS/9012). No market variants deviate from this standard.
Power Ratings: Measured under SAE J1349 standards. Output consistent across all applications (Vauxhall TIS Doc. V‑A20NHT‑01).
Vauxhall Technical Information System (TIS): Docs V‑A20NHT‑01, V20‑8905
VCA Type Approval Database (VCA/EMS/9012)
SAE International: J1349 Engine Power Certification Standards
The Vauxhall A20NHT was used exclusively in Vauxhall's high-performance Epsilon II platform derivatives with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts and upgraded cooling in the Insignia OPC and bespoke exhaust routing in the Cascada—and from 2016 the Insignia OPC received updated HPFP components, creating minor service part interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the timing cover (Vauxhall TIS V‑A20NHT‑01). The 7th VIN digit is 'F' for 2.0L turbo petrol engines in Insignia OPC. Visual identification: red-painted cam cover with 'OPC' badge; high-pressure fuel rail visible on intake side; twin-scroll turbo with integrated exhaust manifold. Critical differentiation from lower-output A20NFT: A20NHT has higher boost (1.3 bar vs 1.0 bar), reinforced internals, and distinct ECU calibration (Bosch 0285000250). HPFP part number changed in 2016—pre-2016 units use #12618598, post-2016 use #12618612 per TSB‑20‑014.
The A20NHT's primary reliability risk is high-pressure fuel pump (HPFP) degradation under aggressive or track use, with elevated incidence in pre-2016 builds. Vauxhall internal data from 2017 indicated a measurable increase in lean misfire codes after 60,000 km in high-load duty cycles, while UK DVSA MOT statistics show excellent emissions compliance but occasional turbo actuator faults linked to soot ingress. Extended high-boost operation without cooldown accelerates turbo bearing wear, making oil quality and driving habits critical.
Analysis derived from Vauxhall technical bulletins (2014–2018) and UK DVSA failure statistics (2016–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL 20-SE.
Comprehensive technical documentation and regulatory references
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VAUXHALL Official Site
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
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DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
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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.
GOV.UK: Vehicle Approval
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VCA Certification Portal
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