The Audi CTUA diesel engine is a 1,968 cc, inline — four turbo — diesel unit produced between 2015 and 2020. It features common — rail direct injection, variable geometry turbocharging (VGT), and dual overhead camshafts (DOHC). Delivering 110 kW (150 PS) in base tune and up to 140 kW (190 PS) in higher outputs, with torque ranging from 340 Nm to 400 Nm, this engine was engineered for responsive mid — range performance and improved fuel efficiency in compact and mid — size Audi mod…
All CTUA models (2015–2020) meet Euro 6b emissions standards with SCR-assisted aftertreatment (VCA UK Type Approval #VCA/EMS/6789).
The Audi CTUA diesel is a 1,968 cc inline-four turbo-diesel engineered for compact and mid-size models (2015–2020). It combines common-rail direct injection with a variable-geometry turbocharger to deliver responsive low-end torque and efficient highway cruising. Designed to meet Euro 6b emissions standards, it balances performance with regulated environmental compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,968 cc | |
Fuel type | Diesel | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged (VGT) | |
Bore × stroke | 81.0 mm × 95.5 mm | |
Power output | 110–140 kW (150–190 PS) | |
Torque | 340–400 Nm @ 1,750–3,000 rpm | |
Fuel system | Bosch CRS 2-20 (up to 2,000 bar), CP4 pump | |
Emissions standard | Euro 6b | |
Compression ratio | 16.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable-geometry turbo (Honeywell GT1749V) | |
Timing system | Double-row roller chain (long-life design) | |
Oil type | Audi Longlife-05 (SAE 5W-30) | |
Dry weight | 165 kg |
The Audi CTUA was used across Audi's 8V/B9/C7 platforms with longitudinal mounting. This engine received platform-specific adaptations-shorter intake manifolds in the A3 (8V) and revised EGR routing in the A4 B9-and from 2015 the facelifted A6 C7 adopted SCR-based aftertreatment, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The CTUA's primary reliability risk is high-pressure fuel pump (CP4) wear, with elevated incidence in regions with substandard diesel. Internal Audi service data from 2018 indicated over 25% of pre-2017 units required CP4 replacement before 120,000 km, while UK DVSA MOT records show fuel system faults contributing to emissions test failures. Poor fuel quality and extended service intervals increase pump wear, making fuel specification and filter changes critical.
Analysis derived from Audi technical bulletins (2015-2020) and UK DVSA failure statistics (2016-2022). 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 CTUA engine is generally robust when maintained properly. Early models (2015–2017) are prone to CP4 fuel pump wear if non-compliant diesel is used. Later units (post-2017) with improved fuel filtration show better longevity. Using Audi Longlife-05 oil and adhering to service intervals significantly enhances reliability beyond 150,000 km.
Top issues include CP4 high-pressure fuel pump wear, DPF clogging, EGR and intake carbon buildup, and turbo actuator sticking. These are documented in Audi SIBs and field reports. Fuel-related faults are most frequent in areas with poor diesel quality. Regular filter changes and correct fluid usage mitigate most risks.
The CTUA engine was used in the A3 (8V), A4 (B9), A6 (C7), and Q5 (8R) from 2015 to 2020. Key variants include the 2.0 TDI 150 PS and 190 PS. All models feature SCR and AdBlue. It was not used in performance (S/RS) trims or earlier platform generations.
Yes, the CTUA responds well to ECU remapping. Stage 1 tunes typically yield +30–50 kW safely, as stock internals handle increased torque. However, over-tuning can accelerate DPF and turbo wear. Supporting mods (intercooler, exhaust) are recommended for higher stages. Always use reputable tuners familiar with Audi diesel systems.
In combined driving, the CTUA achieves 4.8–5.5 L/100km (51–58 mpg UK). Highway consumption can drop to ~4.2 L/100km (67 mpg), while city driving may reach 6.2 L/100km. Real-world figures depend on driving style, but it remains one of Audi's most efficient 2.0L diesels of its era.
Yes. The CTUA is an interference engine. If the timing chain fails or jumps, piston-to-valve contact will occur, causing severe internal damage. Although the chain is designed for life, any signs of wear or noise must be investigated immediately to prevent catastrophic failure.
Audi specifies SAE 5W-30 oil meeting Longlife-05 standards. This low-ash formulation protects the DPF and EGR system from contamination. Oil changes should occur every 15,000 km or annually. Using non-compliant oil risks sludge buildup and aftertreatment damage.
Comprehensive technical documentation and regulatory references
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AUDI Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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