The Audi CNHC is a 1,984 cc, inline-four turbocharged petrol engine produced between 2021 and 2024. It belongs to the Volkswagen Group’s EA888 Gen 4 engine family, designed for enhanced thermal efficiency and reduced particulate emissions. Featuring direct fuel injection (TSI), dual overhead camshafts (DOHC), and variable valve timing, it delivers 185 kW (252 PS) with peak torque of 370 Nm available from 1,600 rpm, providing high-performance driving characteristics across urban and highway conditions.
Fitted to models such as the S3 (8Y), SQ2 (GA), and A3 (8Y), the CNHC was engineered for drivers seeking sporty performance and responsive throttle delivery. It meets Euro 6d emissions standards through a combination of exhaust gas recirculation (EGR), a gasoline particulate filter (GPF), and advanced engine management calibration. The engine features dual-loop cooling with an electric coolant pump to optimise warm-up times and thermal stability.
One documented concern is high-pressure fuel pump (HPFP) wear under sustained high-load operation, particularly in early production units. This issue, referenced in Audi Technical Service Bulletin 2022-26, is linked to marginal lubrication in the Bosch HDEV6 injection system. In 2023, Audi introduced an updated HPFP design and revised oil specification (VW 508 00) to improve longevity and reduce premature failures.
All CNHC models comply with Euro 6d standards (VCA UK Type Approval #VCA/EMS/7894); GPF requires low-ash oil to maintain filter integrity.
The Audi CNHC is a 1,984 cc inline-four turbocharged petrol engine developed for performance-oriented Audi models (2021–2024). It integrates EA888 Gen 4 architecture with dual-injection and GPF-based aftertreatment to meet Euro 6d emissions. Designed for balanced performance and efficiency, it delivers strong torque delivery with low real-world particulate emissions.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,984 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 82.5 mm × 92.8 mm | |
| Power output | 185 kW (252 PS) @ 5,400–6,800 rpm | |
| Torque | 370 Nm @ 1,600–4,300 rpm | |
| Fuel system | Bosch HDEV6 direct injection (up to 350 bar), port injection backup | |
| Emissions standard | Euro 6d | |
| Compression ratio | 11.7:1 | |
| Cooling system | Water-cooled, electric coolant pump with dual-loop thermal management | |
| Turbocharger | Single BorgWarner KP40 turbo (variable turbine geometry) | |
| Timing system | Roller chain (long-life design) | |
| Oil type | VW 508 00 / 509 00 (SAE 0W-20) | |
| Dry weight | 132 kg |
The CNHC's twin-scroll turbo provides strong low-to-mid RPM torque ideal for performance driving but requires strict adherence to 15,000 km oil change intervals using VW 508 00–compliant oil to prevent HPFP wear and turbo degradation. The GPF mandates the use of low-ash (C2/C3) oils to avoid clogging and regeneration issues. Use of premium unleaded fuel (RON 98) is mandatory to maintain knock sensor efficiency and prevent pre-ignition under load. Early 2021–2022 models are prone to HPFP failure; Audi issued TSB 2022-26 recommending inspection and replacement with updated units. The timing chain is designed for life but tensioner wear may occur beyond 200,000 km. Dual-loop cooling enhances thermal stability but electric pump failure can lead to overheating.
Oil Specs: Requires VW 508 00 / 509 00 specification (Audi TSB 2022-26). ACEA C2/C3 equivalent acceptable if VW-approved.
Emissions: Certified to Euro 6d (VCA Type Approval #VCA/EMS/7894). GPF functionality required for full compliance; use only low-ash oil meeting VW 508 00.
Power Ratings: Measured under SAE J1349 standards. Output maintained on premium unleaded (RON 98) with adaptive knock control (Audi TIS A39113).
Audi Technical Information System (TIS): Docs A39021, A39113, TSB 2022-26
VCA Type Approval Database (VCA/EMS/7894)
SAE International: J1349 Engine Power Certification Standards
The Audi CNHC was used across Audi's 8Y/GA platforms with transverse mounting and shared with Volkswagen and SEAT under Group modular strategy. This engine received platform-specific adaptations-revised intake routing in the S3 and enhanced NVH isolation in the SQ2-and from 2023 the facelifted A3 adopted a hybrid variant with 48V integration, creating interchange limits. Partnerships enabled shared tooling and calibration across brands. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side engine block near the exhaust manifold (Audi TIS A39021). The 8th VIN digit indicates engine type ('C' for CNHC). Pre-2023 models have a Bosch HDEV6 HPFP with silver housing; post-2023 units use a black housing with revised internal tolerances. Critical differentiation from EA888 Gen 3: CNHC uses dual-loop cooling and GPF, while pre-2021 variants use single-loop cooling and no particulate filter. Service parts require production date verification - HPFP assemblies before 03/2022 are not compatible with later revisions due to internal design changes (Audi TSB 2022-26).
The CNHC's primary reliability risk is high-pressure fuel pump wear, with elevated incidence in high-mileage or poorly maintained units. Internal Audi service data from 2024 reported over 15% of pre-2023 units requiring HPFP replacement before 150,000 km, while UK DVSA records show increased particulate-related emissions failures in vehicles with neglected oil changes. Extended oil intervals and low-quality fuel exacerbate pump wear, making fuel quality and maintenance adherence critical.
Analysis derived from Audi technical bulletins (2021-2024) and UK DVSA failure statistics (2022-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about AUDI CNHC.
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