The Audi A8 (D3/4E) facelift of 2005, specifically the 4.2 BiTDI V8 (326 hp) quattro DPF Tiptronic variant, represented a significant evolution of Audi’s flagship luxury sedan. Produced from January 2005 to 2007, this model sat at the top of the A8 range, offering a blend of performance, technology, and refinement. It was positioned as a direct competitor to the BMW 7 Series and Mercedes-Benz S-Class, aiming to deliver a uniquely Audi experience within the full-size luxury segment. The D3 platform, also known as the 4E internally, was a major step forward for Audi, incorporating aluminum space frame construction for reduced weight and increased rigidity.
Technical Specifications
| Brand | Audi |
| Model | A8 |
| Generation | A8 (D3, 4E, facelift 2005) |
| Type (Engine) | 4.2 BiTDI V8 (326 Hp) quattro DPF Tiptronic |
| Start of production | January, 2005 |
| End of production | 2007 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 13.3-13.5 l/100 km (17.7 – 17.4 US mpg, 21.2 – 20.9 UK mpg, 7.5 – 7.4 km/l) |
| Fuel consumption (extra urban) | 7.2-7.3 l/100 km (32.7 – 32.2 US mpg, 39.2 – 38.7 UK mpg, 13.9 – 13.7 km/l) |
| Fuel consumption (combined) | 9.4-9.6 l/100 km (25 – 24.5 US mpg, 30.1 – 29.4 UK mpg, 10.6 – 10.4 km/l) |
| CO2 emissions | 253-258 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 5.9 sec |
| Acceleration 0 – 62 mph | 5.9 sec |
| Acceleration 0 – 60 mph | 5.6 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 6 kg/Hp, 167.6 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 334.2 Nm/tonne |
| Power | 326 Hp @ 3750 rpm |
| Power per litre | 78.9 Hp/l |
| Torque | 650 Nm @ 1600-3500 rpm (479.42 lb.-ft. @ 1600-3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | BVN |
| Engine displacement | 4134 cm3 (252.27 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 83 mm (3.27 in.) |
| Piston Stroke | 95.5 mm (3.76 in.) |
| Compression ratio | 16.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | BiTurbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 10 l (10.57 US qt | 8.8 UK qt) |
| Coolant | 14.9 l (15.74 US qt | 13.11 UK qt) |
| Kerb Weight | 1945 kg (4287.99 lbs.) |
| Max. weight | 2545 kg (5610.76 lbs.) |
| Max load | 600 kg (1322.77 lbs.) |
| Trunk (boot) space – minimum | 500 l (17.66 cu. ft.) |
| Fuel tank capacity | 90 l (23.78 US gal | 19.8 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load with brakes (8%) | 2300 kg (5070.63 lbs.) |
| Permitted trailer load with brakes (12%) | 2300 kg (5070.63 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 95 kg (209.44 lbs.) |
| Length | 5062 mm (199.29 in.) |
| Width | 1894 mm (74.57 in.) |
| Height | 1444 mm (56.85 in.) |
| Wheelbase | 2944 mm (115.91 in.) |
| Front track | 1629 mm (64.13 in.) |
| Rear (Back) track | 1615 mm (63.58 in.) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle (turning diameter) | 12.1 m (39.7 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 6 gears, automatic transmission Tiptronic |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Independent on trapezoidal lever |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 235/55 R17 |
| Wheel rims size | 8J x 17 |
Powertrain & Engine Architecture
The heart of this A8 variant is the 4.2-liter BVN V8 diesel engine. This engine utilizes a Bi-Turbo setup, employing two turbochargers to deliver substantial power and torque across a broad RPM range. The engine features common rail direct injection, allowing for precise fuel delivery and optimized combustion. The DOHC (Double Overhead Camshaft) valvetrain, with four valves per cylinder, further enhances breathing and efficiency. The engine’s 16.5:1 compression ratio is typical for a high-performance diesel, contributing to its thermal efficiency. Paired with the engine is a six-speed Tiptronic automatic transmission. This transmission offers both fully automatic operation and the ability for the driver to manually select gears, providing a degree of control. The Tiptronic system uses a torque converter for smooth launches and low-speed driving, while also offering quick and precise shifts.
Driving Characteristics
The 4.2 BiTDI A8 offered a unique driving experience. The substantial 650 Nm (479 lb-ft) of torque, available from just 1600 rpm, provided effortless acceleration and strong in-gear performance. While not as overtly sporty as some of its gasoline-powered rivals, the diesel A8 delivered a relaxed and confident cruising experience. The Tiptronic transmission, while generally smooth, could sometimes feel slightly hesitant during quick downshifts compared to more modern transmissions. The quattro all-wheel-drive system provided excellent traction in all weather conditions, enhancing stability and control. The gear ratios were tuned for a balance between fuel efficiency and performance, prioritizing comfortable highway cruising over outright acceleration.
Equipment & Trim Levels
The 4.2 BiTDI variant typically came equipped with a high level of standard features. This included leather upholstery, wood trim, multi-zone climate control, a premium sound system, and a comprehensive suite of safety features such as ABS, traction control, and multiple airbags. Optional extras included adaptive cruise control, a navigation system, massaging seats, and a rear-seat entertainment system. The interior design emphasized luxury and comfort, with high-quality materials and meticulous attention to detail. The dashboard layout was clean and intuitive, with a focus on ease of use.
Chassis & Braking
The A8’s chassis featured an aluminum space frame, contributing to its lightweight construction and high torsional rigidity. The suspension system utilized an independent multi-link setup at the front and an independent trapezoidal lever setup at the rear, providing a comfortable and controlled ride. Ventilated disc brakes were fitted on all four wheels, providing ample stopping power. The braking system was further enhanced by ABS (Anti-lock Braking System) and electronic brake-force distribution.
Market Reception & Comparison
The 4.2 BiTDI A8 was generally well-received by automotive critics. It was praised for its powerful engine, comfortable ride, and luxurious interior. However, some critics noted that the diesel engine could be slightly noisy compared to its gasoline counterparts. Compared to the 3.2-liter V6 A8, the 4.2 BiTDI offered significantly more performance and torque, but at a higher price point. Compared to the 4.0-liter gasoline V8, the diesel offered superior fuel economy and a broader torque curve. Reliability was generally good, although the complex Bi-Turbo system and common rail injection system could potentially require more maintenance over the long term.
Legacy
The Audi A8 (D3/4E) 4.2 BiTDI V8 remains a desirable used car today, particularly for those seeking a blend of luxury, performance, and fuel efficiency. The BVN engine, while complex, is generally considered to be robust and reliable if properly maintained. Parts availability is generally good, although some specialized components may be more difficult to source. The A8’s aluminum space frame construction and advanced technology continue to impress, making it a compelling alternative to more conventional luxury sedans. The model represents a pivotal moment in Audi’s history, showcasing the brand’s commitment to innovation and engineering excellence.
