The Audi A4 Avant (B9 8W) 40 TDI Mild Hybrid S tronic, produced from September 2020 to 2024, represents a significant iteration of Audi’s popular compact executive estate. Positioned as a mid-range offering within the B9 Avant lineup, this variant combined a fuel-efficient diesel engine with mild hybrid technology and Audi’s renowned S tronic dual-clutch transmission. It aimed to deliver a balance of performance, economy, and practicality for the discerning European driver, with limited availability in other markets. This model falls within the facelifted B9 generation (8W), introduced in 2019, featuring revised styling and updated technology compared to the pre-facelift models.
Technical Specifications
| Brand | Audi |
| Model | A4 |
| Generation | A4 Avant (B9 8W, facelift 2019) |
| Type (Engine) | 40 TDI (204 Hp) Mild Hybrid S tronic |
| Start of production | September, 2020 |
| End of production | 2024 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Station wagon (estate) |
| Seats | 5 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 5.2-6.0 l/100 km (45.2 – 39.2 US mpg) |
| CO2 emissions (WLTP) | 136-157 g/km |
| Fuel consumption (urban) | 5.4-5.6 l/100 km (43.6 – 42 US mpg) |
| Fuel consumption (extra urban) | 4.2-4.6 l/100 km (56 – 51.1 US mpg) |
| Fuel consumption (combined) | 4.7-5.0 l/100 km (50 – 47 US mpg) |
| CO2 emissions (NEDC) | 123-131 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7.6 sec |
| Acceleration 0 – 62 mph | 7.6 sec |
| Acceleration 0 – 60 mph | 7.2 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Emission standard | Euro 6d-ISC-FCM |
| Weight-to-power ratio | 7.6 kg/Hp |
| Weight-to-torque ratio | 3.9 kg/Nm |
| Power | 204 Hp @ 3800-4200 rpm |
| Torque | 400 Nm @ 1750-3250 rpm (295.02 lb.-ft.) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | DTPA |
| Engine displacement | 1968 cm3 (120.09 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 81 mm (3.19 in.) |
| Piston Stroke | 95.5 mm (3.76 in.) |
| Compression ratio | 15.5:1 |
| 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 | 11.9 l (12.57 US qt | 10.47 UK qt) |
| Kerb Weight | 1550 kg (3417.17 lbs.) |
| Max. weight | 2175 kg (4795.05 lbs.) |
| Max load | 625 kg (1377.89 lbs.) |
| Trunk (boot) space – minimum | 495 l (17.48 cu. ft.) |
| Trunk (boot) space – maximum | 1495 l (52.8 cu. ft.) |
| Fuel tank capacity | 40 l (10.57 US gal | 8.8 UK gal) |
| AdBlue tank capacity | 12 l (3.17 US gal | 2.64 UK gal) |
| Max. roof load | 90 kg (198.42 lbs.) |
| Permitted trailer load (brakes 8%) | 1900 kg (4188.78 lbs.) |
| Permitted trailer load (brakes 12%) | 1700 kg (3747.86 lbs.) |
| Permitted trailer load (no brakes) | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 80 kg (176.37 lbs.) |
| Length | 4762 mm (187.48 in.) |
| Width | 1847 mm (72.72 in.) |
| Width including mirrors | 2022 mm (79.61 in.) |
| Height | 1460 mm (57.48 in.) |
| Wheelbase | 2820 mm (111.02 in.) |
| Front track | 1572 mm (61.89 in.) |
| Rear track | 1555 mm (61.22 in.) |
| Front overhang | 899 mm (35.39 in.) |
| Rear overhang | 1043 mm (41.06 in.) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle | 11.6 m (38.06 ft.) |
| Drivetrain Architecture | ICE and electric motor drive 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 | Disc |
| Assisting systems | ABS |
| Steering type | Steering rack and pinion |
| Power steering | Electric |
| Tires size | 225/50 R17 |
| Wheel rims size | 7.5 J x 17 |
INTRODUCTION
The Audi A4 Avant (B9 8W) 40 TDI Mild Hybrid S tronic, launched in 2020 as part of the facelifted B9 generation, offered a compelling package for buyers seeking a practical and efficient premium estate car. The “40 TDI” designation signified a 2.0-liter turbocharged diesel engine producing 204 horsepower. The inclusion of “Mild Hybrid” indicated the integration of a 48-volt electrical system and a small electric motor, contributing to improved fuel economy and reduced emissions. This variant occupied a sweet spot in the A4 Avant range, providing a balance between performance and running costs, appealing to families and business users alike. It was primarily sold in the European market, where diesel estates remain popular.
Powertrain & Engine Architecture
At the heart of the 40 TDI is the Volkswagen Group’s EA288 engine family, specifically the DTPA code. This 2.0-liter inline-four diesel engine utilizes a common rail direct injection system, delivering fuel at pressures up to 2,500 bar for optimized combustion. A single turbocharger with variable geometry turbine (VGT) provides forced induction, enhancing both low-end torque and overall power output. The engine features four valves per cylinder and a sophisticated exhaust gas recirculation (EGR) system to minimize NOx emissions. The mild hybrid system incorporates a belt starter generator (BSG) that recovers energy during braking and allows for extended engine-off coasting, further improving fuel efficiency. The seven-speed S tronic dual-clutch transmission provides rapid and smooth gear changes, contributing to a responsive driving experience. This transmission is known for its efficiency and ability to handle the engine’s torque output effectively.
Driving Characteristics
The 40 TDI S tronic Avant delivers a refined and comfortable driving experience. The 400 Nm (295 lb-ft) of torque available from 1750-3250 rpm provides ample pulling power for everyday driving and overtaking maneuvers. While not overtly sporty, the 7.6-second 0-100 km/h (0-62 mph) acceleration is more than adequate for most situations. The S tronic transmission contributes to a seamless power delivery, and the mild hybrid system helps to smooth out gear changes and reduce engine vibrations. Compared to the more powerful 45 TDI variants, the 40 TDI offers a slightly less aggressive driving experience, prioritizing fuel economy and refinement. Manual transmission versions, while available, were less common and offered a more engaging, albeit less effortless, driving experience.
Equipment & Trim Levels
The 40 TDI Mild Hybrid S tronic Avant typically came well-equipped, reflecting Audi’s premium positioning. Standard features included Audi’s MMI Navigation Plus infotainment system with a 10.1-inch touchscreen display, Audi Virtual Cockpit (digital instrument cluster), three-zone automatic climate control, and a comprehensive suite of safety features such as lane departure warning, automatic emergency braking, and adaptive cruise control. Interior upholstery was typically a combination of cloth and leatherette, with optional upgrades to full leather available. Common optional extras included a panoramic sunroof, metallic paint finishes, and upgraded sound systems. Trim levels varied slightly depending on the market, but generally followed Audi’s ‘Sport,’ ‘S line,’ and ‘Black Edition’ structure, with increasing levels of equipment and styling enhancements.
Chassis & Braking
The B9 A4 Avant features a sophisticated chassis design, utilizing 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 a mid-range model, typically featured slightly smaller wheels and tires compared to the higher-performance versions, contributing to a more compliant ride. Braking duties are handled by ventilated discs at the front and solid discs at the rear, providing adequate stopping power for everyday driving. Anti-lock braking system (ABS) and electronic stability control (ESC) are standard features, enhancing safety and stability.
Market Reception & Comparison
The Audi A4 Avant 40 TDI Mild Hybrid S tronic was generally well-received by automotive critics. It was praised for its fuel efficiency, comfortable ride, and refined interior. Compared to the higher-output TDI variants, the 40 TDI offered a more affordable entry point into the A4 Avant range without sacrificing too much performance. Its fuel economy was notably better than that of the petrol-powered A4 models, making it a popular choice for high-mileage drivers. Competitors included the BMW 3 Series Touring, Mercedes-Benz C-Class Estate, and Volvo V60, all of which offered similar levels of performance and refinement.
Legacy
The EA288 engine family, including the DTPA code used in the 40 TDI, has proven to be relatively reliable, although preventative maintenance is crucial. The mild hybrid system has also demonstrated good long-term durability. On the used car market, the A4 Avant 40 TDI Mild Hybrid S tronic represents a sensible and well-rounded option. Potential buyers should look for vehicles with a full service history and evidence of regular maintenance. The combination of fuel efficiency, practicality, and Audi’s build quality ensures that this variant remains a desirable choice for those seeking a premium compact executive estate.
