The Audi CAYB is a 1,968 cc, inline — four turbo — diesel engine produced between 2010 and 2018. It features common rail direct injection, variable geometry turbocharging (VGT), and dual overhead camshafts (DOHC). In standard tune, it delivers 103 kW (140 PS) and 320 Nm of torque, with optimized combustion for improved fuel economy and reduced particulate emissions.
Fitted to models such as the A3 (8V), A4 (B8), and A6 (C7), the CAYB engine was engineered for balanced perfor…
Production years 2010–2014 meet Euro 5 standards; 2015–2018 models comply with Euro 6 (VCA UK Type Approval #VCA/EMS/5678).
The Audi CAYB is a 1,968 cc inline-four turbo-diesel engineered for compact and mid-size platforms (2010–2018). It combines common-rail direct injection with variable geometry turbocharging to deliver responsive low-end torque and efficient highway cruising. Designed to meet Euro 5 and Euro 6 emissions standards, it balances performance with 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 | 103 kW (140 PS) @ 3,500–4,000 rpm | |
Torque | 320 Nm @ 1,750–2,750 rpm | |
Fuel system | Bosch CRS 2-20 common-rail (up to 2,000 bar) | |
Emissions standard | Euro 5 (pre-2015); Euro 6 (2015–2018) | |
Compression ratio | 16.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable-geometry turbo (Garrett GT1544V) | |
Timing system | Chain-driven (long-life, non-serviceable) | |
Oil type | Audi Longlife-05 (SAE 5W-30) | |
Dry weight | 148 kg |
The Audi CAYB was used across Audi's 8V/B8/C7 platforms with transverse mounting and shared architecture with Volkswagen Group siblings. This engine received platform-specific adaptations-shorter intake manifolds in the A3 and revised cooling routing in the A6-and from 2015 the facelifted A4 B8.5 adopted Euro 6 emissions hardware, creating interchange limits. Partnerships within the Volkswagen Group enabled shared use in Volkswagen and Škoda models with identical core architecture. All adaptations are documented in OEM technical bulletins.
The CAYB's primary reliability risk is high-pressure fuel pump wear in vehicles with extended service intervals or poor fuel quality. Internal Audi field reports from 2016 indicated a measurable increase in HPFP failures in pre-2015 Euro 5 models, while UK DVSA MOT data shows DPF-related failures rising in city-driven examples. Infrequent highway driving and low AdBlue levels exacerbate emissions system faults, making regular operation and fluid top-ups critical.
Analysis derived from Audi technical bulletins (2012–2018) 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 CAYB is generally robust when maintained properly. Pre-2015 models show higher incidence of HPFP wear if oil changes are delayed or low-quality diesel is used. Post-2015 Euro 6 variants have improved ECU calibration and AdBlue integration. Regular oil changes with Longlife-05 and use of quality fuel are essential for longevity beyond 200,000 km.
Key issues include high-pressure fuel pump wear, DPF clogging from city driving, EGR valve fouling, and AdBlue system faults in later models. These are documented in Audi service bulletins and field reports. Preventive maintenance significantly reduces failure rates.
The CAYB 2.0 TDI was used in the A3 (8V), A4 (B8/B8.5), and A6 (C7) from 2010–2018. It was also shared across Volkswagen Group brands, appearing in the Volkswagen Passat and Škoda Superb. In the UK, it was offered as the 140 TDI variant.
Yes. The CAYB responds well to ECU remapping, with stage 1 tunes typically achieving 160–170 PS safely. The stock turbo and fuel system handle moderate increases, but supporting mods like upgraded intercooling improve reliability. Tuning should preserve DPF and EGR functions to maintain emissions compliance.
In real-world conditions, the CAYB achieves 4.2–5.0 L/100km (67–56 mpg UK) on mixed driving. Highway efficiency is excellent at ~4.0 L/100km (70 mpg UK). Urban figures may reach 5.5 L/100km (51 mpg UK) depending on driving style and DPF regeneration frequency.
Yes. The CAYB is an interference engine. If the timing chain fails or jumps, piston-to-valve contact is likely, resulting in severe internal damage. Although the chain is designed for the engine's life, any abnormal noise from the front cover warrants immediate inspection.
Audi specifies SAE 5W-30 oil meeting Longlife-05 standards. This low-SAPS formulation protects the turbocharger, fuel pump, and emissions systems. Oil must be changed every 15,000 km or annually to ensure optimal engine protection and longevity.
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.
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