The Alfa Romeo 670 05 2721 – Petrol is a 1,750 cc, inline — four turbocharged petrol engine produced between 2015 and 2020. It features direct fuel injection, variable valve timing (Dual VVT), and a twin — scroll turbocharger, delivering 125 kW (170 PS) and 250 Nm of torque. This engine, part of the Fiat Global Small Engine (GSE) family, was engineered for responsive urban driving and efficient highway cruising.
Fitted to models such as the Alfa Romeo Giulietta and MiTo, the 67…
All units produced between 2015 and 2020 meet Euro 6b emissions standards (VCA UK Type Approval #VCA/EMS/6701). No Euro 5 variant of this engine exists.
The Alfa Romeo 670 05 2721 – Petrol is a 1,750 cc inline-four turbocharged petrol engine developed for compact platforms (2015–2020). It combines high-pressure direct injection with a twin-scroll turbocharger to deliver strong low-end torque and linear power delivery. Designed to meet Euro 6b standards, it balances Alfa Romeo's sporty driving ethos with modern efficiency and emissions requirements.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,750 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 80.5 mm × 85.8 mm | |
Power output | 125 kW (170 PS) @ 5,500 rpm | |
Torque | 250 Nm @ 1,750–4,500 rpm | |
Fuel system | Fiat MultiAir2 with direct injection (up to 200 bar) | |
Emissions standard | Euro 6b | |
Compression ratio | 9.8:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single twin-scroll turbo (IHI RHF4) | |
Timing system | Timing chain (lifetime service interval) | |
Oil type | Fiat 9.55535-S3 M1 0W-30 | |
Dry weight | 117 kg |
The Alfa Romeo 670 05 2721 – Petrol was used across Alfa Romeo's 952/332 platforms with transverse mounting and shared architecture with Fiat and Lancia. This engine received platform-specific tuning-for enhanced throttle response in the Giulietta and revised exhaust manifolds in the MiTo-and from 2017 received updated turbocharger oil routing to improve reliability, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
The 670 05 2721 – Petrol's primary reliability risk is turbocharger bearing wear in early builds, with elevated incidence in urban-driven examples with frequent cold starts. Internal Fiat Group quality reports from 2018 indicated a significant share of pre-2017 engines required turbo replacement before 120,000 km, while UK DVSA records show increased EGR-related faults in stop-start traffic. Short-trip driving and delayed oil changes exacerbate thermal stress, making service adherence and driving pattern awareness critical.
Analysis derived from Alfa Romeo technical bulletins (2015-2020) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The 670 05 2721 – Petrol offers strong performance and efficiency, but early models (2015-2016) had reliability concerns, particularly turbocharger wear. Later revisions (post-2017) improved oil routing and durability. When maintained properly—with timely oil changes and proper cooldown—it can exceed 200,000 km. Avoid frequent short trips and always use Fiat 9.55535-S3 M1 0W-30 oil for best results.
The most documented issues are turbocharger bearing wear, cold-start timing chain rattle, EGR and intake carbon buildup, and throttle body malfunctions. These are covered in Alfa Romeo and Fiat Group service bulletins. Driving style and oil quality significantly impact reliability, especially in urban environments with frequent stop-start cycles.
This 1.8L TBi engine was used in the Alfa Romeo Giulietta (2015-2020) and MiTo (2015-2018). It was also shared with the Fiat 500X (2016-2020) and Lancia Ypsilon (2017-2020). All models were Euro 6b compliant. No 4C or Stelvio applications exist for this specific engine variant.
Yes. The engine responds well to ECU remapping, with stage 1 tunes typically adding +30–40 kW safely. The stock turbo and internals handle increased torque, but supporting mods (intercooler, exhaust) are recommended for higher stages. Tuning must preserve emissions functionality to avoid reliability issues. Always use a reputable tuner familiar with MultiAir2 systems.
Competitive for its class. In a Giulietta 1.8 TBi, combined consumption is approximately 6.8 L/100 km (~41 mpg UK). Highway driving can achieve 5.5 L/100 km (~51 mpg UK), while city use may reach 8.0 L/100 km (~35 mpg UK). Real-world economy depends on driving style, but 35–45 mpg UK is typical for mixed use.
Yes. The engine has an interference design, meaning if the timing chain fails or jumps, the pistons can strike the open valves, causing catastrophic damage. While the chain is rated for life, tensioner failure can lead to slack. Any cold-start rattle should prompt immediate inspection to prevent major engine damage.
Alfa Romeo specifies Fiat 9.55535-S3 M1 0W-30 synthetic oil. This formulation is critical for turbocharger and MultiAir2 actuator protection. Oil changes should be performed every 15,000 km or annually. Using incorrect oil can accelerate turbo and valvetrain wear, especially under high-load conditions.
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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