The Audi A8 (D4, 4H) 4.2 BiTDI V8 quattro Tiptronic represents a high-performance iteration of the third-generation A8, produced between 2010 and 2013. Positioned as a flagship luxury sedan, this variant combined a potent diesel V8 engine with Audi’s renowned quattro all-wheel-drive system and an eight-speed Tiptronic automatic transmission. It occupied the upper echelon of the D4 A8 lineup, offering a blend of performance, refinement, and technology aimed at discerning buyers seeking a powerful yet efficient grand tourer. The D4 generation A8, built on the Volkswagen Group’s D4 platform (shared with the Porsche Panamera and Bentley Continental GT), aimed to elevate Audi’s presence in the full-size luxury segment.
Technical Specifications
| Brand | Audi |
| Model | A8 |
| Generation | A8 (D4, 4H) |
| Type (Engine) | 4.2 BiTDI V8 (350 Hp) quattro Tiptronic |
| Start of production | 2010 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 9.3 l/100 km (25.3 US mpg, 30.4 UK mpg, 10.8 km/l) |
| Fuel consumption (extra urban) | 6.3 l/100 km (37.3 US mpg, 44.8 UK mpg, 15.9 km/l) |
| Fuel consumption (combined) | 7.4 l/100 km (31.8 US mpg, 38.2 UK mpg, 13.5 km/l) |
| CO2 emissions | 195 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 5.5 sec |
| Acceleration 0 – 62 mph | 5.5 sec |
| Acceleration 0 – 60 mph | 5.2 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 5.7 kg/Hp, 175.4 Hp/tonne |
| Weight-to-torque ratio | 2.5 kg/Nm, 401 Nm/tonne |
| Power | 350 Hp @ 4000 rpm |
| Power per litre | 84.7 Hp/l |
| Torque | 800 Nm @ 1750-2750 rpm (590.05 lb.-ft. @ 1750-2750 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | CDSB |
| 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 | 9.5 l (10.04 US qt | 8.36 UK qt) |
| Coolant | 12.2 l (12.89 US qt | 10.73 UK qt) |
| Kerb Weight | 1995 kg (4398.22 lbs.) |
| Max. weight | 2660 kg (5864.3 lbs.) |
| Max load | 665 kg (1466.07 lbs.) |
| Trunk (boot) space – minimum | 510 l (18.01 cu. ft.) |
| Trunk (boot) space – maximum | 1142 l (40.33 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 | 5137 mm (202.24 in.) |
| Width | 1949 mm (76.73 in.) |
| Width including mirrors | 2111 mm (83.11 in.) |
| Height | 1460 mm (57.48 in.) |
| Wheelbase | 2992 mm (117.8 in.) |
| Front track | 1644 mm (64.72 in.) |
| Rear (Back) track | 1635 mm (64.37 in.) |
| Front overhang | 1003 mm (39.49 in.) |
| Rear overhang | 1142 mm (44.96 in.) |
| Ride height (ground clearance) | 120 mm (4.72 in.) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle (turning diameter) | 12.3 m (40.35 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission |
| 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 | Electric Steering |
| Tires size | 235/60 R17 |
| Wheel rims size | 8.0J x 17 |
INTRODUCTION
The Audi A8 (D4) 4.2 BiTDI V8 quattro Tiptronic, produced from 2010 to 2013, was a top-tier variant of Audi’s flagship sedan. It represented a significant offering in the luxury performance segment, particularly in European markets where diesel engines were highly favored. This model combined the prestige of the A8 nameplate with a powerful and efficient diesel powertrain, all-wheel drive capability, and a sophisticated automatic transmission. The 4.2 BiTDI engine, coupled with the eight-speed Tiptronic gearbox, aimed to deliver both exhilarating performance and impressive fuel economy for a vehicle of its size and weight. It was positioned above the 3.0 TDI models and below the even more exclusive 6.3-liter W12 variant.
Powertrain & Engine Architecture
At the heart of the A8 4.2 BiTDI lies the CDSB engine code, a 4.134-liter V8 diesel engine. This engine utilizes a sophisticated bi-turbocharger system, employing two turbochargers in series to minimize turbo lag and maximize power delivery across the rev range. The engine features a common rail direct injection system, operating at extremely high pressures to ensure efficient combustion and reduced emissions. The valvetrain employs double overhead camshafts (DOHC) with four valves per cylinder. The eight-speed Tiptronic automatic transmission, a staple of Audi’s performance models, provides smooth and responsive gear changes. It allows for both fully automatic operation and manual gear selection via steering wheel-mounted paddles or the gear selector. The transmission is designed to handle the substantial torque output of the engine and contribute to both performance and fuel efficiency.
Driving Characteristics
The 4.2 BiTDI-equipped A8 offered a distinctly different driving experience compared to its siblings. The substantial 800 Nm (590 lb-ft) of torque, available from a low 1750 rpm, provided effortless acceleration and strong in-gear performance. The eight-speed Tiptronic transmission was well-matched to the engine’s characteristics, offering quick and seamless shifts. While not as overtly sporty as some of its rivals, the A8 4.2 BiTDI delivered a refined and confident driving experience. The quattro all-wheel-drive system provided excellent traction in all weather conditions, enhancing stability and control. Compared to the 3.0 TDI, the 4.2 BiTDI offered significantly more power and torque, resulting in noticeably quicker acceleration and a more relaxed cruising experience. The manual transmission options available on lower trims were not offered with this engine, emphasizing the focus on effortless performance and luxury.
Equipment & Trim Levels
The A8 4.2 BiTDI typically came generously equipped, reflecting its position as a flagship model. Standard features included leather upholstery, heated and ventilated front seats with massage function, a premium sound system, a navigation system with MMI touch interface, and a comprehensive suite of safety features. Optional extras included advanced driver-assistance systems such as adaptive cruise control, lane keeping assist, and a night vision system. Interior trim options included a variety of wood veneers, aluminum accents, and leather colors. Exterior options included different wheel designs and paint colors. The overall ambiance was one of understated luxury and technological sophistication.
Chassis & Braking
The A8 D4 featured an advanced chassis design aimed at balancing comfort and handling. The front suspension utilized an independent multi-link setup, while the rear suspension employed an independent trapezoidal link design. This configuration provided a smooth and controlled ride, even on uneven surfaces. The braking system consisted of ventilated discs on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) and electronic stability control (ESC) were standard features, enhancing safety and stability. The suspension was often equipped with adaptive air suspension, allowing the driver to adjust the ride height and damping characteristics to suit their preferences.
Market Reception & Comparison
The Audi A8 4.2 BiTDI was generally well-received by automotive critics. It was praised for its powerful and efficient engine, refined ride quality, and luxurious interior. However, some critics noted that the A8 lacked the outright sporting character of some of its rivals, such as the BMW 7 Series and Mercedes-Benz S-Class. Compared to the A8 3.0 TDI, the 4.2 BiTDI offered superior performance but at a higher price point. Fuel economy remained competitive, despite the increased power output. Reliability was generally good, although the complex bi-turbocharger system and advanced electronics could potentially require more expensive maintenance over the long term.
Legacy
The Audi A8 (D4) 4.2 BiTDI V8 quattro Tiptronic remains a desirable used car today, particularly for those seeking a blend of performance, luxury, and efficiency. The CDSB engine, while complex, has proven to be relatively durable when properly maintained. The eight-speed Tiptronic transmission is also known for its reliability. However, potential buyers should be aware of the potential for higher maintenance costs associated with the bi-turbocharger system and advanced electronic systems. The A8 4.2 BiTDI represents a high point in Audi’s engineering prowess, offering a compelling alternative to traditional gasoline-powered luxury sedans.
