The Audi CR is a 1,781 cc, inline — five petrol engine produced between 2000 and 2007. Part of Audi's naturally aspirated 1.8L and 2.0L engine family, it features a 20 — valve DOHC configuration and sequential multi — point fuel injection (MPI). Delivering 98 kW (133 PS) and 173 Nm of torque, it provides smooth, linear power delivery ideal for everyday driving.
Fitted to models including the Audi A4 (B6/B7), A6 (C5), and TT (8N), the CR engine was engineered for refinement and re…

Production years 2000–2003 meet Euro 3 standards; 2004–2007 models comply with Euro 4 .
The Audi CR is a 1,781 cc inline-five petrol engine designed for longitudinal applications (2000–2007). It combines multi-point fuel injection with a 20-valve head and variable intake geometry to deliver smooth power delivery. Engineered to meet Euro 4 standards in later production, it balances refinement with mechanical simplicity.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,781 cc | |
Fuel type | Petrol | |
Configuration | Inline-5, DOHC, 20-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 81.0 mm × 72.6 mm | |
Power output | 98 kW (133 PS) @ 6,000 rpm | |
Torque | 173 Nm @ 4,500 rpm | |
Fuel system | Bosch Motronic M3.8.3 sequential MPI | |
Emissions standard | Euro 3 (2000–2003); Euro 4 (2004–2007) | |
Compression ratio | 10.3:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Timing belt (interval: 120,000 km or 6 years) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 158 kg |
The Audi CR was used across Audi's B6/B7/C5 platforms with longitudinal mounting and shared within the Volkswagen Group for transverse applications. This engine received platform-specific adaptations-shorter intake manifolds in the A4 and revised cooling routing in the A6-and from 2004 updated IMRA components for improved longevity, creating interchange limits. All adaptations are documented in OEM technical bulletins.
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Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. 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 CR engine is known for mechanical simplicity and durability when properly maintained. It lacks turbochargers and direct injection, reducing complexity. However, adherence to timing belt intervals (120,000 km or 6 years) is critical due to interference design. Regular use of quality oil (VW 502 00) and RON 95 petrol ensures long-term reliability.
Key issues include timing belt failure, IMRA system malfunctions, oil leaks from the valve cover gasket, and ignition coil/spark plug wear. These are documented in Audi service bulletins, particularly SIB 203 003 for IMRA improvements. Urban driving and neglected maintenance exacerbate these issues.
The CR engine was used in the Audi A4 (B6/B7, 2000–2007), A6 (C5, 2000–2005), and TT (8N, 2000–2006). It was phased out in favour of turbocharged and direct-injection variants post-2007, marking the end of naturally aspirated 1.8L 20V production.
While the CR is not commonly tuned due to its naturally aspirated design, performance gains can be achieved through camshaft upgrades, intake and exhaust modifications, and ECU remapping. However, power increases are modest compared to turbocharged engines. Supporting modifications like high-flow injectors and upgraded ignition are recommended for reliability.
In mixed driving, the CR achieves approximately 8.5–9.5 L/100km (30–33 mpg UK). Highway efficiency is around 7.0 L/100km (40 mpg UK), while city driving may reach 11.0 L/100km (26 mpg UK). Real-world figures depend on driving style, vehicle weight, and condition of ignition and intake systems.
Yes, the CR is an interference engine. If the timing belt fails, pistons will contact open valves, resulting in severe internal damage. Adhering to the 120,000 km or 6-year replacement interval is critical to avoid costly repairs.
Audi specifies VW 502 00 (SAE 5W-40) synthetic oil. This formulation is essential for valvetrain and timing belt longevity. Oil changes should be performed every 15,000 km or annually to maintain engine health and prevent sludge buildup.
Comprehensive technical documentation and regulatory references
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Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
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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