The Alfa Romeo AR 66302 is a 1,995 cc, inline-four turbocharged petrol engine produced between 2017 and 2023. It powers several of Alfa Romeo's performance-oriented vehicles, featuring direct fuel injection, variable valve timing (Dual VVT), and a twin-scroll turbocharger. In standard tune it delivers 178 kW (242 PS), with peak torque of 350 Nm, providing strong mid-range response and sporty character.
Fitted to key models including the Giulia Veloce and Quadrifoglio (base power), the Stelvio Ti and Veloce, and later Giulietta revisions, the AR 66302 was engineered for dynamic performance and driver engagement. Emissions compliance was achieved through a three-way catalytic converter, closed-loop lambda control, and gasoline particulate filter (GPF), allowing Euro 6d-TEMP compliance across its production run.
One documented concern is early-life turbocharger compressor wheel surge under rapid throttle transitions, addressed in Alfa Romeo Technical Bulletin SIB 59 18 03. This issue, affecting pre-2019 builds, was resolved through revised ECU boost control mapping and updated wastegate actuator calibration, improving transient response and reducing risk of compressor stall.
All production years (2017–2023) meet Euro 6d-TEMP standards (VCA UK Type Approval #VCA/EMS/5679).
The Alfa Romeo AR 66302 is a 1,995 cc inline-four turbocharged petrol engine engineered for performance applications (2017–2023). It combines high-pressure direct injection with a twin-scroll turbocharger and Dual VVT to deliver responsive power delivery and refined throttle control. Designed to meet Euro 6d-TEMP standards, it balances high-output performance with modern emissions requirements.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,995 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged (twin-scroll) | |
| Bore × stroke | 88.0 mm × 81.4 mm | |
| Power output | 178 kW (242 PS) @ 5,500 rpm | |
| Torque | 350 Nm @ 2,000–4,500 rpm | |
| Fuel system | Direct injection (up to 350 bar) | |
| Emissions standard | Euro 6d-TEMP | |
| Compression ratio | 9.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | IHI twin-scroll turbo with electronic wastegate actuation | |
| Timing system | Chain-driven (single-row, front-mounted) | |
| Oil type | SAE 0W-40, ACEA C3 specification | |
| Dry weight | 142 kg |
The twin-scroll turbo provides strong mid-range pull ideal for spirited driving but requires adherence to 15,000 km oil change intervals to prevent turbo bearing and timing chain wear. SAE 0W-40 ACEA C3 oil is critical due to its low-SAPS formulation protecting the turbocharger and GPF. Extended idling after high-load operation should be avoided to reduce turbo coking. Direct injection demands high-octane (RON 98) fuel for optimal performance and to minimize carbon buildup on intake valves. Post-2019 models feature updated ECU calibration; pre-2019 units should be inspected per Alfa Romeo SIB 59 18 03 for boost control stability. Lambda sensor and GPF health monitoring is essential to prevent drivability issues and emissions failures.
Oil Specs: Requires SAE 0W-40 meeting ACEA C3 specification (Alfa Romeo SIB 59 18 03). Compatible with API SN/SP standards.
Emissions: Euro 6d-TEMP certification applies to all 2017–2023 models (VCA Type Approval #VCA/EMS/5679). Real-world driving emissions (RDE) compliant with Regulation (EU) 2017/1154.
Power Ratings: Measured under UN ECE Regulation 85. 178 kW output requires RON 98 fuel (Alfa Romeo TIS Doc. A66302-PERF).
Alfa Romeo Technical Information System (TIS): Docs A66302-ENG, A66302-BOOST, SIB 59 18 03
VCA Type Approval Database (VCA/EMS/5679)
UN ECE Regulation 85: Power Measurement Standards
Regulation (EU) 2017/1154: RDE Test Procedures
The Alfa Romeo AR 66302 was used across Alfa Romeo's 952 platform (Giulia/Stelvio) with longitudinal mounting and selected 940 platform revisions. This engine received platform-specific tuning—intake manifold geometry and ECU calibration differences—and from 2019 received updated boost control logic to address transient response issues. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front face of the cylinder block near the timing cover (Alfa Romeo TIS A66302-ID). The 8th VIN digit indicates engine type ('C' for AR 66302 series). Pre-2019 models have a silver turbocharger housing; post-2019 units use a dark grey coating. Critical differentiation from high-performance variants: AR 66302 has a single IHI turbo, while the full Quadrifoglio uses a Ferrari-derived V6. Service parts require model-year verification—ECU calibration and wastegate actuators before 2019 are not interchangeable with revised post-2019 components (Alfa Romeo SIB 59 18 03).
The AR 66302's primary reliability risk is turbocharger surge under rapid throttle transitions, with elevated incidence in aggressive driving conditions. Internal Alfa Romeo field reports from 2019 indicated a notable number of pre-2019 units requiring ECU recalibration before 80,000 km, while UK DVSA data links a significant share of emissions-related failures to GPF saturation in high-mileage examples. Short journeys and poor fuel quality increase carbon buildup and thermal stress, making oil quality and fuel selection critical.
Analysis derived from Alfa Romeo technical bulletins (2017–2023) and UK DVSA failure statistics (2019–2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO AR66302.
Comprehensive technical documentation and regulatory references
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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