The Audi A6 Avant (C8) 40 TDI, produced from 2018 to May 2023, represents a compelling blend of practicality, efficiency, and technology within the executive station wagon segment. This variant, powered by a 2.0-liter turbocharged diesel engine and paired with a seven-speed S tronic dual-clutch transmission, occupied a significant position in the A6 Avant lineup as a balance between performance and fuel economy. It served as a popular choice for buyers seeking a refined and capable vehicle for both daily commuting and long-distance travel. The “40 TDI” designation reflects Audi’s power-based naming convention, indicating a power output level within their engine hierarchy.
Technical Specifications
| Brand | Audi |
| Model | A6 |
| Generation | A6 Avant (C8) |
| Type (Engine) | 40 TDI (204 Hp) Mild Hybrid S tronic |
| Start of production | 2018 |
| End of production | May, 2023 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Station wagon (estate) |
| Seats | 5 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 4.7-5.2 l/100 km (50 – 45.2 US mpg, 60.1 – 54.3 UK mpg, 21.3 – 19.2 km/l) |
| CO2 emissions (WLTP) | 150-165 g/km |
| Fuel consumption (urban) | 5.0-5.3 l/100 km (47 – 44.4 US mpg, 56.5 – 53.3 UK mpg, 20 – 18.9 km/l) |
| Fuel consumption (extra urban) | 4.2-4.7 l/100 km (56 – 50 US mpg, 67.3 – 60.1 UK mpg, 23.8 – 21.3 km/l) |
| Fuel consumption (combined) | 4.5-4.9 l/100 km (52.3 – 48 US mpg, 62.8 – 57.6 UK mpg, 22.2 – 20.4 km/l) |
| CO2 emissions | 119-129 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 8.3 sec |
| Acceleration 0 – 62 mph | 8.3 sec |
| Acceleration 0 – 60 mph | 7.9 sec |
| Maximum speed | 241 km/h (149.75 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 8.4 kg/Hp, 119.3 Hp/tonne |
| Weight-to-torque ratio | 4.3 kg/Nm, 233.9 Nm/tonne |
| Power | 204 Hp @ 3750-4200 rpm |
| Torque | 400 Nm @ 1750-3000 rpm (295.02 lb.-ft. @ 1750-3000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | DFBA |
| Engine displacement | 1968 cm3 (120.09 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 5.5 l (5.81 US qt | 4.84 UK qt) |
| Coolant capacity | 10.8 l (11.41 US qt | 9.5 UK qt) |
| Kerb Weight | 1710 kg (3769.9 lbs.) |
| Max. weight | 2330 kg (5136.77 lbs.) |
| Max load | 620 kg (1366.87 lbs.) |
| Trunk (boot) space – minimum | 565 l (19.95 cu. ft.) |
| Fuel tank capacity | 63 l (16.64 US gal | 13.86 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load with brakes (12%) | 2000 kg (4409.25 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 95 kg (209.44 lbs.) |
| Length | 4939 mm (194.45 in.) |
| Width | 1886 mm (74.25 in.) |
| Width including mirrors | 2110 mm (83.07 in.) |
| Height | 1467 mm (57.76 in.) |
| Wheelbase | 2924 mm (115.12 in.) |
| Front track | 1630 mm (64.17 in.) |
| Rear track | 1617 mm (63.66 in.) |
| Front overhang | 920 mm (36.22 in.) |
| Rear overhang | 1095 mm (43.11 in.) |
| Drag coefficient (Cd) | 0.28 |
| Minimum turning circle | 12.1 m (39.7 ft.) |
| Drivetrain Architecture | ICE and electric motor drive the front wheels |
| Drive wheel | Front wheel drive |
| Number of gears | 7 |
| Gearbox type | Automatic transmission S tronic |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
Powertrain & Engine Architecture
The heart of the A6 Avant 40 TDI is the DFBA engine, a 2.0-liter inline-four cylinder diesel engine. This engine utilizes a sophisticated common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion. A turbocharger with an intercooler further enhances performance by forcing more air into the cylinders. The engine produces 204 horsepower at 3750-4200 rpm and a substantial 400 Nm (295 lb-ft) of torque between 1750 and 3000 rpm. The inclusion of a mild hybrid system (MHEV) adds a 48-volt electrical system and a belt starter generator (BSG). This system allows for features like extended engine-off coasting, regenerative braking, and smoother start-stop operation, contributing to improved fuel efficiency. The seven-speed S tronic dual-clutch transmission provides rapid and seamless gear changes, enhancing both performance and driving comfort. This transmission is known for its efficiency and responsiveness compared to traditional torque-converter automatics.
Driving Characteristics
The 40 TDI variant delivers a refined and comfortable driving experience. While not the most powerful A6 Avant available, the 204 hp and 400 Nm of torque provide ample performance for everyday driving and overtaking maneuvers. The S tronic transmission contributes to brisk acceleration, with a 0-60 mph time of around 7.9 seconds. The engine’s torque curve is broad, providing strong pull throughout the rev range. Compared to the more powerful 45 TDI or the petrol-powered variants, the 40 TDI prioritizes fuel economy and smoothness over outright speed. The automatic transmission is well-tuned for everyday use, offering both automatic and manual shift modes. The mild hybrid system is largely imperceptible to the driver, working seamlessly in the background to optimize efficiency.
Equipment & Trim Levels
The A6 Avant 40 TDI typically came well-equipped, reflecting its position as a premium executive car. Standard features often included Audi’s MMI touch response infotainment system with a dual-screen setup, leather upholstery, three-zone automatic climate control, and a suite of driver-assistance systems such as lane departure warning and automatic emergency braking. Optional extras could include features like a Bang & Olufsen sound system, adaptive cruise control, a head-up display, and matrix LED headlights. Trim levels varied by market, but generally offered increasing levels of luxury and technology. The base trim provided a comfortable and well-equipped experience, while higher trims added more premium materials and advanced features.
Chassis & Braking
The A6 Avant (C8) features a sophisticated chassis design with independent multi-link suspension at both the front and rear axles. This setup provides a comfortable ride quality while maintaining good handling characteristics. The 40 TDI variant, being positioned in the middle of the range, typically came equipped with ventilated disc brakes on all four wheels. The braking system is augmented by ABS (Anti-lock Braking System) and electronic stability control. The suspension is tuned to balance comfort and handling, offering a composed ride even on uneven surfaces.
Market Reception & Comparison
The Audi A6 Avant 40 TDI was generally well-received by automotive critics. It was praised for its refined engine, comfortable ride, and spacious interior. Fuel economy was a particular strength, making it an attractive option for drivers covering long distances. Compared to other trims in the A6 Avant lineup, the 40 TDI offered a compelling balance between performance and efficiency. The more powerful 45 TDI provided more exhilarating performance but at the expense of fuel economy, while the petrol-powered variants offered a different driving experience but often lacked the torque of the diesel engine.
Legacy
The DFBA engine, found in the A6 Avant 40 TDI, has proven to be a relatively reliable powertrain. While diesel engines are subject to more stringent emissions regulations and potential maintenance concerns related to the diesel particulate filter (DPF), the DFBA engine has generally demonstrated good durability. In the used car market, the A6 Avant 40 TDI remains a popular choice, offering a blend of practicality, comfort, and efficiency. Regular maintenance, including timely servicing and DPF regeneration, is crucial for ensuring the long-term reliability of this vehicle.
