Technical Specifications
| Brand | Audi |
| Model | A4 |
| Generation | A4 (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 | Sedan |
| Seats | 5 |
| Doors | 4 |
| Combined fuel consumption (WLTP) | 5.0-5.8 l/100 km (47 – 40.6 US mpg) |
| CO2 emissions (WLTP) | 131-152 g/km |
| Fuel consumption (urban) | 5.3-5.5 l/100 km (44.4 – 42.8 US mpg) |
| Fuel consumption (extra urban) | 4.0-4.4 l/100 km (58.8 – 53.5 US mpg) |
| Fuel consumption (combined) | 4.5-4.8 l/100 km (52.3 – 49 US mpg) |
| CO2 emissions (NEDC) | 118-126 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7.4 sec |
| Acceleration 0 – 62 mph | 7.4 sec |
| Acceleration 0 – 60 mph | 7 sec (Calculated) |
| Maximum speed | 210 km/h (130.49 mph) |
| Emission standard | Euro 6d-ISC-FCM |
| Weight-to-power ratio | 7.4 kg/Hp |
| Weight-to-torque ratio | 3.8 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 | 1500 kg (3306.93 lbs.) |
| Max. weight | 2100 kg (4629.71 lbs.) |
| Max load | 600 kg (1322.77 lbs.) |
| Trunk (boot) space (minimum) | 460 l (16.24 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 | 1431 mm (56.34 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) | 0.25 |
| Minimum turning circle | 11.6 m (38.06 ft.) |
| Drivetrain Architecture | ICE and electric motor, Front wheel drive |
| Number of gears | 7 |
| Gearbox type | Automatic transmission S tronic |
| Front suspension | Independent multi-link |
| Rear suspension | Independent multi-link |
| 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 |
The Audi A4 B9.5 40 TDI represents a refinement of the fourth-generation A4, launched in 2015 and facelifted in late 2019. This particular variant, powered by a 2.0-liter turbocharged diesel engine and utilizing a 7-speed S tronic dual-clutch transmission, was introduced in September 2020 and continued in production through 2024. The “40 TDI” designation signifies a specific power output level within Audi’s naming convention. The inclusion of mild-hybrid technology (MHEV) underscores Audi’s commitment to improving fuel economy and reducing emissions. Positioned as a mid-range offering, the 40 TDI aimed to provide a compelling blend of performance, efficiency, and premium features for discerning buyers.
Powertrain & Engine Architecture
At the heart of the A4 40 TDI lies the DTPA engine, a 2.0-liter inline-four cylinder diesel engine. This engine utilizes a common-rail direct injection system, delivering fuel at extremely high pressure for optimized combustion. A single turbocharger with an intercooler provides forced induction, boosting power and torque. The engine boasts a compression ratio of 15.5:1, contributing to its efficiency. The mild-hybrid system incorporates a 48-volt electrical system and a belt starter generator (BSG). The BSG allows for extended start-stop functionality, regenerative braking, and a small amount of electric assistance during acceleration. The 7-speed S tronic dual-clutch transmission offers rapid and smooth gear changes, enhancing both performance and driving comfort. This transmission is known for its efficiency and responsiveness, contributing to the overall driving experience.
Driving Characteristics
The 204 horsepower and 400 Nm (295 lb-ft) of torque delivered by the 40 TDI powertrain provide a balanced driving experience. Acceleration from 0 to 100 km/h (0-62 mph) takes approximately 7.4 seconds. While not as overtly sporty as higher-powered A4 variants, the 40 TDI offers ample power for everyday driving and comfortable highway cruising. The S tronic transmission contributes to a seamless power delivery, and the mild-hybrid system provides a subtle boost during acceleration. Compared to the manual transmission versions, the S tronic offers quicker shifts and greater convenience. Compared to the more powerful 45 TDI, the 40 TDI prioritizes fuel efficiency over outright performance, making it a more economical choice for those who prioritize long-distance comfort and lower running costs.
Equipment & Trim Levels
The A4 40 TDI typically came well-equipped as standard. Features generally included Audi’s MMI infotainment system with a touchscreen display, Audi Virtual Cockpit (digital instrument cluster), three-zone automatic climate control, and a suite of driver-assistance systems such as lane departure warning and automatic emergency braking. Interior upholstery was typically a combination of cloth and leatherette, with optional upgrades to full leather available. Trim levels varied by market, but common options included sport suspension, panoramic sunroof, and premium sound systems. Exterior styling elements, such as wheel designs and chrome accents, also differed depending on the chosen trim package.
Chassis & Braking
The A4 40 TDI utilizes a sophisticated chassis design featuring independent multi-link suspension at both the front and rear. This suspension setup provides a comfortable ride quality while maintaining good handling characteristics. The front brakes are ventilated discs, while the rear brakes are solid discs. Anti-lock braking system (ABS) is standard, along with electronic stability control (ESC). The steering system is an electric power-assisted rack and pinion system, offering precise and responsive steering feel. The weight distribution is well-balanced, contributing to the car’s stability and handling prowess.
Market Reception & Comparison
The Audi A4 40 TDI was generally well-received by automotive critics. It was praised for its refined engine, comfortable ride, and advanced technology. Fuel economy was a particular strength, with the mild-hybrid system contributing to impressive real-world figures. Compared to other trims in the A4 lineup, the 40 TDI offered a compelling value proposition, providing a good balance of performance and efficiency. Competitors in the premium compact segment, such as the BMW 320d and Mercedes-Benz C220d, offered similar levels of performance and technology, but the A4 40 TDI often stood out for its sophisticated interior and user-friendly infotainment system.
Legacy
The Audi A4 B9.5 40 TDI powertrain has proven to be relatively reliable, with few widespread issues reported. The 2.0-liter TDI engine is known for its durability, and the S tronic transmission, while requiring regular maintenance, is generally robust. On the used car market, these models hold their value reasonably well, reflecting the A4’s reputation for quality and refinement. The mild-hybrid technology, while not a full hybrid system, represents an important step towards greater fuel efficiency and reduced emissions, making these models increasingly attractive to environmentally conscious buyers. The A4 40 TDI continues to be a popular choice for those seeking a premium compact sedan that offers a blend of performance, comfort, and economy.
