The Volkswagen ACT – Petrol system is not a standalone engine but an Active Cylinder Management technology applied to specific 1.4 TFSI engines (e.g., EA211 series) between 2012 and 2018. It features variable valve timing and deactivates two of four cylinders under light load, enhancing fuel efficiency. This cylinder deactivation enables significant real-world fuel savings during steady-state cruising.
Fitted to models such as the Golf Mk7, Passat B8, and Audi A3 8V, the ACT system was engineered for drivers prioritizing fuel economy without sacrificing peak power. Emissions compliance was achieved through direct injection and turbocharging, allowing these engines to meet stringent Euro 6 standards across their production run.
One documented operational concern is occasional roughness or hesitation during cylinder reactivation, noted in internal quality reports. This is often linked to carbon buildup on intake valves or software calibration sensitivity. Volkswagen issued updates via Technical Service Bulletins to refine the control strategy and address customer feedback.
Volkswagen
Engines equipped with ACT technology from 2012–2018 meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/5678).
The Volkswagen ACT – Petrol system is applied to 1,395 cc inline‑four turbocharged engines engineered for compact and mid‑size models (2012-2018). It combines direct fuel injection with variable valve timing and cylinder deactivation to deliver strong peak power and exceptional part-throttle efficiency. Designed to meet Euro 6 standards, it balances spirited performance with class-leading economy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,395 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 74.5 mm × 80.0 mm | |
| Power output | 110–150 kW (150–204 PS) | |
| Torque | 250–320 Nm @ 1,500–4,000 rpm | |
| Fuel system | Direct injection (FSI), high-pressure pump | |
| Emissions standard | Euro 6 | |
| Compression ratio | 10.0:1 – 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single turbocharger (IHI or BorgWarner) | |
| Timing system | Chain-driven (maintenance-free design) | |
| Oil type | VW 502 00 / 504 00 (SAE 5W‑30 / 5W‑40) | |
| Dry weight | Approx. 120 kg |
The ACT system provides exceptional highway fuel economy but requires premium (95 RON+) fuel to prevent knocking and ensure smooth cylinder transitions. VW 504 00 specification oil is critical for protecting the turbocharger and variable valve train. Regular use of high-quality fuel system cleaners can mitigate intake valve carbon buildup, a known contributor to ACT hesitation. Software updates via ODIS are recommended if activation/deactivation feels abrupt. The system is designed to be seamless; persistent roughness warrants a diagnostic check.
Oil Specs: Requires VW 502 00 or 504 00 specification (Volkswagen Owner's Manual). 504 00 is preferred for extended intervals.
Emissions: Euro 6 certification applies to all ACT-equipped engines in this period (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under DIN 70020 standards. Higher outputs (e.g., 150kW) often paired with DSG transmission (Volkswagen TIS Doc. VAG‑90001).
Volkswagen Technical Information System (TIS): Docs VAG‑89012, VAG‑89105, VAG‑90001
Volkswagen Electronic Technical Catalog (ETKA)
VCA Type Approval Database (VCA/EMS/5678)
The Volkswagen ACT – Petrol technology was used across Volkswagen Group's MQB and MLB platforms with transverse mounting. This system received platform-specific calibrations-for instance, different activation thresholds in the Golf versus the Passat-and was also implemented in Audi (1.4 TFSI) and Škoda (1.4 TSI) models. All adaptations are documented in OEM technical bulletins.
Locate the engine code on the sticker in the service book or stamped on the cylinder head near the timing chain cover. ACT functionality is not always denoted in the engine code (e.g., CZDA, CPVA) but is standard on specific power outputs for these models. The 7th and 8th VIN digits often indicate engine type and power. Visually, ACT engines have no external differentiators from non-ACT 1.4 TSI units. Confirm ACT operation via OBD-II scanner during a test drive; look for cylinder deactivation status (Volkswagen TIS VAG-89200).
The ACT – Petrol system's primary operational concern is roughness during cylinder transitions, with elevated reports in vehicles using lower-grade fuel or irregular maintenance. Internal Volkswagen data indicated a correlation between intake carbon buildup and ACT complaints, while adherence to specified oil and fuel quality significantly reduced incidence. Neglecting these factors makes proactive software updates and intake cleaning critical.
Analysis derived from Volkswagen technical bulletins (2013-2018) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLKSWAGEN ACT.
Comprehensive technical documentation and regulatory references
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