The Alfa Romeo AR 30550 is a 1,995 cc, inline-four turbocharged petrol engine produced between 2021 and 2023. It features gasoline direct injection (GDI), dual overhead camshafts (DOHC), and a twin-scroll turbocharger, delivering 169 kW (230 PS) at 5,700 rpm and 360 Nm of torque from 2,000–4,500 rpm. This engine was engineered as the mid-tier petrol unit for Alfa Romeo’s premium compact and mid-size platforms, balancing performance and efficiency.
Fitted to the 952 Giulia and 956 Stelvio, the AR 30550 was tuned for dynamic responsiveness and sporty driving dynamics. Its design emphasizes near 50:50 weight distribution, longitudinal mounting, and rapid throttle response. Emissions compliance was achieved via a close-coupled three-way catalytic converter and adaptive lambda control, enabling Euro 6d-TEMP certification across its production run.
One documented concern is premature wear of the high-pressure fuel pump drive mechanism, particularly in vehicles subjected to frequent short trips. Highlighted in Alfa Romeo Service Information Bulletin 81/2022, this issue stems from inadequate lubrication in the cam follower system. From 2022, revised drive components with enhanced metallurgy were introduced to improve durability.
All production years 2021–2023 meet Euro 6d-TEMP emissions standards (VCA UK Type Approval #VCA/EMS/7550).
The Alfa Romeo AR 30550 is a 1,995 cc inline-four turbocharged petrol engine designed for premium applications (2021–2023). It utilizes gasoline direct injection and a twin-scroll turbocharger to deliver strong mid-range torque and responsive throttle characteristics. Designed to meet Euro 6d-TEMP emissions standards, it balances performance with regulated efficiency.
| 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 × 81.5 mm | |
| Power output | 169 kW (230 PS) @ 5,700 rpm | |
| Torque | 360 Nm @ 2,000–4,500 rpm | |
| Fuel system | Bosch HDEV6 direct injection (up to 350 bar) | |
| Emissions standard | Euro 6d-TEMP | |
| Compression ratio | 9.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | IHI twin-scroll turbo with electronically controlled wastegate | |
| Timing system | Chain-driven (double-row primary, single-row secondary) | |
| Oil type | Fiat 9.55535-S2 (SAE 0W-30) | |
| Dry weight | 139 kg |
The twin-scroll turbo provides strong mid-RPM torque ideal for spirited driving but requires strict adherence to 15,000 km oil change intervals using Fiat 9.55535-S2 (0W-30) oil to prevent turbo bearing and timing chain wear. Extended idling after high-load operation should be avoided to reduce coking in the turbo actuator. Direct injection necessitates periodic intake valve cleaning. The high-pressure fuel pump is sensitive to frequent cold starts; early models (pre-2022) are prone to drive wear; updated components mitigate this risk. Emissions systems require full operating temperature for accurate diagnostics.
Oil Specs: Requires Fiat 9.55535-S2 (0W-30) specification (Alfa Romeo SIB 81/2022). Critical for turbo and chain longevity.
Emissions: Certified to Euro 6d-TEMP across all model years (VCA Type Approval #VCA/EMS/7550). Compliant under WLTP testing.
Power Ratings: Measured under ECE R85 standards. Output optimized for 95 RON fuel (Alfa Romeo TIS Doc. 60.74.95).
Alfa Romeo Technical Information System (TIS): Docs 60.74.95, SIB 81/2022
VCA Type Approval Database (VCA/EMS/7550)
ISO 1585:1996 Road vehicles — Test method for the measurement of gaseous pollutant emissions
The Alfa Romeo AR 30550 was used across Alfa Romeo's 952/956 platforms with longitudinal rear-transverse mounting and shared architecture with Stellantis. This engine received platform-specific tuning—slightly revised cooling in the 956 Stelvio and enhanced throttle mapping in the 952 Giulia—and from 2022 the facelifted 952/956 models adopted revised high-pressure fuel pump drives, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front face of the cylinder block, below the intake manifold (Alfa Romeo TIS 60.74.95). The 8th VIN digit indicates engine type ('B' for AR 30550 petrol turbo). Pre-2022 models have a black valve cover with exposed fuel pump drive; post-2022 units feature revised metallurgy. Critical differentiation from AR 30143: AR 30550 has a higher compression ratio, reinforced connecting rods, and performance-tuned ECU. Service parts require production date verification—fuel pump drives for pre-2022 builds are incompatible with post-LCI models due to internal redesign (Alfa Romeo SIB 81/2022).
The AR 30550's primary reliability risk is high-pressure fuel pump drive wear on early builds, with elevated incidence in urban use. Internal Alfa Romeo quality reports from 2023 noted a significant share of pre-2022 engines requiring pump replacement before 90,000 km, while UK DVSA records indicate fuel system DTCs as a leading cause of emissions test failures. Frequent short trips and delayed maintenance increase wear, making adherence to service intervals critical.
Analysis derived from Alfa Romeo technical bulletins (2021-2023) and UK DVSA failure statistics (2022-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO AR30550.
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