The Audi A4 (B9 8W) facelift, specifically the 45 TFSI quattro Mild Hybrid S tronic variant, represents a significant evolution of Audi’s popular executive sedan. Introduced in May 2019 and continuing through May 2020, this model year brought updated styling, enhanced technology, and a refined powertrain to the A4 lineup. Positioned as a mid-to-upper trim level, the 45 TFSI offered a compelling blend of performance, efficiency, and luxury features, appealing to buyers seeking a sophisticated and capable daily driver. It builds upon the foundation of the B9 platform (A4/A5 series), which debuted in 2015, incorporating advancements in mild-hybrid technology and driver assistance systems.
Technical Specifications
| Brand | Audi |
| Model | A4 |
| Generation | A4 (B9 8W, facelift 2019) |
| Type (Engine) | 45 TFSI (245 Hp) quattro Mild Hybrid S tronic |
| Start of production | May, 2019 |
| End of production | May, 2020 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Combined fuel consumption (WLTP) | 7.7-7.9 l/100 km (30.5 – 29.8 US mpg) |
| CO2 emissions (WLTP) | 174-178 g/km |
| Fuel consumption (urban) | 8.5-8.7 l/100 km (27.7 – 27 US mpg) |
| Fuel consumption (extra urban) | 5.3-5.8 l/100 km (44.4 – 40.6 US mpg) |
| Fuel consumption (combined) | 6.5-6.8 l/100 km (36.2 – 34.6 US mpg) |
| CO2 emissions | 146-155 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.8 sec |
| Acceleration 0 – 62 mph | 5.8 sec |
| Acceleration 0 – 60 mph | 5.5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6d – TEMP – EVAP – ISC |
| Weight-to-power ratio | 6.3 kg/Hp |
| Weight-to-torque ratio | 4.2 kg/Nm |
| Power | 245 Hp @ 5000-6500 rpm |
| Torque | 370 Nm @ 1600-4300 rpm (272.9 lb.-ft.) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | DKNA |
| Engine displacement | 1984 cm3 (121.07 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 5.2 l (5.49 US qt | 4.58 UK qt) |
| Kerb Weight | 1545 kg (3406.14 lbs.) |
| Max. weight | 2110 kg (4651.75 lbs.) |
| Max load | 565 kg (1245.61 lbs.) |
| Fuel tank capacity | 58 l (15.32 US gal | 12.76 UK gal) |
| Max. roof load | 90 kg (198.42 lbs.) |
| Permitted trailer load (brakes 8%) | 1700 kg (3747.86 lbs.) |
| Permitted trailer load (brakes 12%) | 1500 kg (3306.93 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 | 1428 mm (56.22 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.) |
| Minimum turning circle | 11.6 m (38.06 ft.) |
| Drivetrain Architecture | ICE and electric motor, All wheel drive |
| Drive wheel | All wheel drive (4×4) |
| 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 (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
Powertrain & Engine Architecture
At the heart of the 45 TFSI lies the 2.0-liter inline-four cylinder engine, designated the DKNA engine code. This powerplant benefits from direct fuel injection and a single turbocharger with an intercooler, producing 245 horsepower at 5000-6500 rpm and 272.9 lb.-ft. of torque between 1600-4300 rpm. The “45 TFSI” designation doesn’t directly correlate to engine displacement; it’s part of Audi’s naming convention reflecting its position within the model range. What sets this variant apart is its incorporation of a 12V mild-hybrid system. This system utilizes a belt starter generator (BSG) and a small lithium-ion battery to enable features like extended engine-off coasting, smoother start-stop operation, and a slight power boost during acceleration. The transmission is a seven-speed S tronic dual-clutch automatic, known for its quick and precise shifts. This transmission is integral to the car’s performance and efficiency, offering both automatic and manual shift modes.
Driving Characteristics
The 45 TFSI quattro delivers a refined and engaging driving experience. The combination of the turbocharged engine and the S tronic transmission results in brisk acceleration – 0 to 60 mph in approximately 5.5 seconds. The quattro all-wheel-drive system provides excellent traction in various conditions, enhancing stability and confidence. Compared to the base A4 models with lower horsepower engines, the 45 TFSI offers noticeably more power and responsiveness. While not as overtly sporty as the S4, it provides ample power for everyday driving and spirited excursions. The mild-hybrid system is largely transparent to the driver, contributing to improved fuel economy without sacrificing performance. The S tronic transmission’s gear ratios are well-tuned for both acceleration and highway cruising.
Equipment & Trim Levels
The 45 TFSI quattro typically came well-equipped as standard. Features included Audi’s Virtual Cockpit (a fully digital instrument cluster), a 10.1-inch touchscreen infotainment system with Apple CarPlay and Android Auto integration, 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 included a Bang & Olufsen premium sound system, navigation, adaptive cruise control, and a head-up display. Trim levels varied slightly by market, but generally offered packages that added features like sport seats, upgraded interior trim, and exterior styling enhancements.
Chassis & Braking
The A4 B9 utilizes a sophisticated chassis design featuring independent multi-link suspension at both the front and rear axles. This setup provides a comfortable ride while maintaining good handling characteristics. The 45 TFSI quattro typically came equipped with ventilated front discs and solid rear discs. The quattro all-wheel-drive system distributes power between the front and rear axles as needed, optimizing traction and stability. The steering is precise and well-weighted, providing a connected feel to the driver.
Market Reception & Comparison
The Audi A4 45 TFSI quattro Mild Hybrid S tronic was generally well-received by automotive critics. It was praised for its refined powertrain, comfortable ride, and advanced technology. Compared to other trims in the A4 lineup, the 45 TFSI offered a significant performance upgrade without the higher price tag of the S4. Fuel economy was considered competitive for its class, and the mild-hybrid system contributed to further improvements. Reliability reports have been generally positive, although some owners have reported minor issues with the infotainment system.
Legacy
The 2.0-liter turbocharged engine with the S tronic transmission has proven to be a durable and reliable powertrain in numerous Audi and Volkswagen models. The mild-hybrid technology introduced in the 45 TFSI represents a step towards greater electrification and improved fuel efficiency. On the used car market, these models hold their value relatively well, particularly those with low mileage and a well-maintained service history. The B9 A4, and specifically the 45 TFSI variant, remains a popular choice for buyers seeking a premium compact executive sedan.
