The Alfa Romeo AR 01655 is a 1,750 cc, inline-four turbocharged petrol engine produced between 2015 and 2020. It forms the core of Alfa Romeo's downsized gasoline lineup, featuring direct fuel injection, variable valve timing (Dual VVT), and a twin-scroll turbocharger. In standard tune it delivers 147 kW (200 PS), with torque peaking at 300 Nm from 1,500 rpm, enabling responsive performance ideal for sporty driving dynamics.
Fitted to key models including the 940 Giulietta, 952 Giulia, and 956 Stelvio, the AR 01655 was engineered to balance spirited performance with improved fuel efficiency over previous naturally aspirated units. Emissions compliance is achieved through a three-way catalytic converter and closed-loop lambda control, allowing Euro 6b certification across its production run for all major European markets.
One documented concern is premature turbocharger wastegate actuator sticking, noted in Alfa Romeo Technical Bulletin 56/2018. This issue arises from carbon buildup and thermal stress on the actuator linkage, leading to boost control faults. From 2018, revised actuator hardware and updated ECU calibration were implemented to improve long-term reliability.
Production years 2015–2017 meet Euro 6b standards; 2018–2020 models comply with Euro 6d-TEMP (VCA UK Type Approval #VCA/EMS/5678).
The Alfa Romeo AR 01655 is a 1,750 cc inline-four turbocharged petrol engine engineered for compact and mid-size performance models (2015–2020). It combines direct fuel injection with a twin-scroll turbocharger to deliver strong low-end torque and linear power delivery. Designed to meet Euro 6 emissions standards, it balances sporty driving character with regulated efficiency.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,750 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged (twin-scroll) | |
| Bore × stroke | 84.0 mm × 80.0 mm | |
| Power output | 147 kW (200 PS) @ 5,750 rpm | |
| Torque | 300 Nm @ 1,500–4,500 rpm | |
| Fuel system | Direct injection (up to 200 bar) | |
| Emissions standard | Euro 6b (2015–2017); Euro 6d-TEMP (2018–2020) | |
| Compression ratio | 9.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | IHI twin-scroll turbo with vacuum-actuated wastegate | |
| Timing system | Chain-driven (single-row, front-mounted) | |
| Oil type | SAE 5W-40, API SN/CF, ACEA C3 | |
| Dry weight | 132 kg |
The twin-scroll turbo provides immediate throttle response and strong mid-range pull, but requires strict adherence to 15,000 km oil service intervals to protect the turbo bearings and timing chain. Use of ACEA C3 5W-40 oil is critical to maintain particulate filter compatibility and reduce turbo coking. Extended idling after high-load operation should be avoided to prevent heat soak in the turbocharger. Direct injectors are prone to deposit buildup; periodic cleaning per Alfa Romeo procedure is recommended. Post-2018 models benefit from updated wastegate actuators and ECU mapping, reducing boost-related faults.
Oil Specs: Requires ACEA C3 5W-40 specification (Alfa Romeo SIB 56/2018). Compatible with API SN/CF standards.
Emissions: Euro 6b certification applies to 2015–2017 models (VCA Type Approval #VCA/EMS/5678). Euro 6d-TEMP applies from 2018 onward.
Power Ratings: Measured under ECE R101 standards. Output assumes premium unleaded (RON 98) fuel quality (Alfa Romeo TIS A1750T06).
Alfa Romeo Technical Information System (TIS): Docs A1750T01, A1750T02, A1750T05, SIB 56/2018
VCA Type Approval Database (VCA/EMS/5678)
European Commission Regulation (EC) No 715/2007
The Alfa Romeo AR 01655 was used across Alfa Romeo's 940/952/956 platforms with transverse mounting in the Giulietta and longitudinal in the Giulia/Stelvio, creating drivetrain-specific adaptations. This engine received platform-specific calibrations-adapted intake manifolds in the 940 and revised cooling layouts in the 952-and from 2018 the facelifted Giulia QV adopted a higher-lift cam profile for improved airflow. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block near the starter motor (Alfa Romeo TIS A1750T07). The 8th VIN digit indicates engine type ('B' for AR 01655). Pre-2018 models have silver valve covers with black intake manifolds; post-2018 units use black valve covers. Critical differentiation from high-output versions: AR 01655 uses IHI RHF3 VJ27 turbo with round compressor housing, while Quadrifoglio variants use larger BorgWarner unit. Service parts require model-year verification - turbo actuators before 06/2018 are incompatible with later revisions per Alfa Romeo SIB 56/2018.
The AR 01655's primary reliability risk is turbocharger wastegate actuator failure, with elevated incidence in short-trip urban use. Internal Alfa Romeo field reports from 2019 indicated a significant number of pre-2018 units required actuator replacement before 100,000 km, while UK DVSA records show increased catalytic converter failures linked to prolonged rich-running conditions. Frequent cold starts and low-speed operation increase carbon buildup, making oil quality and warm-up cycles critical.
Analysis derived from Alfa Romeo technical bulletins (2016-2020) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO AR01655.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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