The Alfa Romeo AR 31010 is a 1,750 cc, inline-four naturally aspirated petrol engine produced between 2015 and 2018. It belongs to the Tigershark family, developed under Fiat Global Small Engine (GSE) architecture, and features MultiAir II variable valve timing, port fuel injection, and dual overhead camshafts. In standard tune it delivers 88 kW (120 PS), with torque output of 162 Nm, primarily used in entry-level Giulietta and MiTo variants.
Fitted to the 940 Giulietta facelift and 334 MiTo restyling, the AR 31010 was engineered for urban efficiency and responsive low-end drivability. Emissions compliance is achieved through a three-way catalytic converter and closed-loop lambda control, meeting Euro 5 standards for all production years, with certain markets receiving enhanced OBD calibration for early Euro 6b alignment.
One documented engineering update is the revision of the intake manifold with improved airflow geometry, introduced in Alfa Romeo Technical Bulletin 70/2016. This addressed early reports of inconsistent cylinder filling at mid-range RPM, improving throttle response and fuel atomization. Later production engines (post-07/2016) feature this updated manifold and recalibrated ECU mapping per engineering change AR-TU-2016-01.
All production years (2015–2018) meet Euro 5 standards; select 2017–2018 units comply with early Euro 6b requirements depending on market (VCA UK Type Approval #VCA/EMS/5687).
The Alfa Romeo AR 31010 is a 1,750 cc inline-four naturally aspirated petrol engine engineered for compact transverse applications (2015–2018). It combines MultiAir II variable valve timing with port fuel injection to deliver linear throttle response and efficient urban performance. Designed to meet Euro 5 emissions standards, it balances cost-effective ownership with everyday usability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,750 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 75.0 mm | |
| Power output | 88 kW (120 PS) @ 6,250 rpm | |
| Torque | 162 Nm @ 4,500 rpm | |
| Fuel system | Bosch ME7.8.10 port injection (up to 4 bar) | |
| Emissions standard | Euro 5 (all); select markets Euro 6b | |
| Compression ratio | 10.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven (single-row, front-mounted) | |
| Oil type | SAE 5W-30 (Alfa Romeo 9.55535-S1 M1) | |
| Dry weight | 128 kg |
The MultiAir II system provides responsive low-RPM torque ideal for city driving but demands consistent use of 95 RON fuel to prevent knock and carbon accumulation. Alfa Romeo 9.55535-S1 M1 (5W-30) oil is essential due to its thermal stability and compatibility with the timing chain. Extended idling should be minimized to reduce valve coking. The port fuel injection system is less prone to intake carbon buildup than direct injection but still requires periodic cleaning of injectors and throttle body. Post-2016 models feature improved intake manifolds; pre-2016 units should be inspected per Technical Bulletin 70/2016. Three-way catalyst longevity depends on consistent lambda sensor function and avoidance of misfire conditions.
Oil Specs: Requires Alfa Romeo 9.55535-S1 M1 specification (5W-30) (Alfa Romeo SIB 70/2016). Supersedes ACEA A1/B1.
Emissions: Euro 5 certification applies to all 2015–2018 models (VCA Type Approval #VCA/EMS/5687). Select 2017–2018 export markets meet early Euro 6b OBD requirements.
Power Ratings: Measured under SAE J1349 standards. 88 kW output requires 95 RON fuel quality and full thermal management (Alfa Romeo TIS Doc. AR-A26024).
Alfa Romeo Technical Information System (TIS): Docs AR-A24689, AR-A25151, SIB 70/2016
VCA Type Approval Database (VCA/EMS/5687)
SAE International: J1349 Engine Power Certification Standards
The Alfa Romeo AR 31010 was used across Alfa Romeo's 940/334 platforms with transverse mounting and shared with select Fiat Chrysler Automobiles models for European applications. This engine received platform-specific adaptations-shorter intake runners in the MiTo and revised exhaust routing in the Giulietta-and from 2016 the facelifted Giulietta received the AR 31010.TU variant with updated intake manifold and ECU calibration, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front cylinder block near the timing cover (Alfa Romeo TIS AR-A24899). The 8th VIN digit indicates engine family ('L' for AR 31010 series). Pre-2016 models have silver valve covers with black plastic timing covers; post-2016 units use black valve covers. Critical differentiation from AR 31010.TU: Original AR 31010 uses Bosch ME7.8.10 ECU with rectangular diagnostic port, while AR 31010.TU uses MEDG17.7.2 with trapezoidal port. Service parts require production date verification - intake manifolds for engines before 07/2016 are incompatible with later units due to internal flow revisions (Alfa Romeo TB 70/2016).
The AR 31010's primary reliability risk is MultiAir II actuator degradation on early builds, with elevated incidence in mixed urban/highway driving. Internal Alfa Romeo quality reports from 2017 indicated a notable share of pre-2016 engines requiring actuator replacement before 90,000 km, while UK DVSA records link a portion of emissions-related MOT failures to lambda sensor degradation in high-mileage units. Short-trip usage and poor fuel quality increase carbon and coking risks, making fuel grade and service adherence critical.
Analysis derived from Alfa Romeo technical bulletins (2015-2018) and UK DVSA failure statistics (2016-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO AR31010.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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