The Audi CTGA is a 1,968 cc, inline-four turbo-diesel engine produced between 2015 and 2020. Part of the Volkswagen Group’s EA288 diesel engine family, it features common rail direct injection, variable geometry turbocharging (VGT), and dual overhead camshafts. It delivers 110 kW (150 PS) with 340 Nm of torque, meeting stringent Euro 6 emissions standards through a combination of exhaust gas recirculation (EGR), diesel particulate filter (DPF), and selective catalytic reduction (SCR) with AdBlue injection.
Fitted primarily to the Audi A3 (8V), A4 (B9), and Q3 (8U) models, including the A3 2.0 TDI, A4 2.0 TDI, and Q3 2.0 TDI trims, the CTGA engine was engineered for balanced performance and efficiency. Its modular diesel system allows for precise fuel metering and combustion control, supporting both urban and highway driving. The engine incorporates start-stop technology and brake energy regeneration to further enhance fuel economy.
One documented concern is excessive carbon buildup in the intake manifold, particularly in vehicles used for frequent short trips. This issue, referenced in Audi Technical Service Bulletin 2017-08, is attributed to EGR system operation under low-temperature conditions. From 2018, Audi introduced revised EGR valve calibration and updated intake manifold design to mitigate deposit accumulation, with later models showing improved resistance to intake fouling.
Production years 2015–2020 meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/6789).
The Audi CTGA is a 1,968 cc inline-four turbo-diesel engine engineered for compact and mid-size models (2015–2020). It combines common rail fuel delivery with variable geometry turbocharging to deliver strong low-end torque and efficient cruising. Designed to meet Euro 6 standards, it balances performance with strict emissions compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,968 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged with variable geometry turbo (VGT) | |
| Bore × stroke | 81.0 mm × 95.5 mm | |
| Power output | 110 kW (150 PS) @ 3,250–4,200 rpm | |
| Torque | 340 Nm @ 1,500–3,000 rpm | |
| Fuel system | Bosch CRS 2-20 common rail (up to 2,000 bar) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 16.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single variable-geometry turbo (Honeywell) | |
| Timing system | Timing chain (interval: 200,000 km or 10 years) | |
| Oil type | VW 505 01 / 507 00 (SAE 5W-30) | |
| Dry weight | 142 kg |
The VGT system provides strong low-RPM torque ideal for daily driving but requires regular highway runs to maintain EGR and DPF functionality. VW 505 01 (5W-30) oil is essential for longevity, particularly in mixed driving conditions. Turbocharger longevity depends on proper warm-up and cool-down cycles. The SCR system requires periodic AdBlue refills and is sensitive to fuel quality; use of non-compliant diesel increases risk of injector coking and DPF blockage. Post-2018 models feature updated EGR calibration; pre-2018 units should be inspected per Audi SIB 2017-08. Emissions systems require adaptation resets after battery disconnection or long-term storage.
Oil Specs: Requires VW 505 01 / 507 00 specification (Audi SIB 2017-08). Compatible with ACEA C2/C3.
Emissions: Euro 6 certification applies to all models (2015–2020) (VCA Type Approval #VCA/EMS/6789).
Power Ratings: Measured under ECE R85 standards. Output maintained with EN 590 diesel (Audi TIS Doc. A25020).
Audi Technical Information System (TIS): Docs A24680, A25142, SIB 2017-08
VCA Type Approval Database (VCA/EMS/6789)
ECE Regulation 85: Uniform provisions concerning the approval of vehicles with regard to emissions
The Audi CTGA was used across Audi's 8V/B9/8U platforms with transverse mounting and shared within the Volkswagen Group for longitudinal applications. This engine received platform-specific adaptations-shorter intake manifolds in the A3 and revised cooling routing in the A4-and from 2018 the facelifted A4 models adopted the updated EGR valve design, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side engine block near the exhaust manifold (Audi TIS A24890). The 8th VIN digit indicates engine family ('C' for EA288 series). Pre-2018 models have silver valve covers with ribbed plastic timing covers; post-2018 units use black valve covers. Critical differentiation from EA288 variants: Original CTGA uses Bosch EDC17CP56 ECU with trapezoidal diagnostic port, while later CKRA uses EDC17C84 with rectangular port. Service parts require production date verification - EGR valves for engines before 06/2018 are incompatible with later units due to calibration and connector changes (Audi SIB 2017-08).
The CTGA's primary reliability risk is intake carbon buildup on neglected units, with elevated incidence in mixed urban use. Internal Audi quality reports from 2018 indicated a notable share of pre-2018 engines requiring EGR and intake cleaning before 120,000 km, while UK DVSA records link a significant portion of emissions-related MOT failures to DPF saturation in city-driven vehicles. Short-trip cycles and delayed maintenance increase EGR and DPF stress, making interval adherence critical.
Analysis derived from Audi technical bulletins (2015-2020) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about AUDI CTGA.
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EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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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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