The Audi A8 (D4, 4H facelift) 4.2 TDI V8 clean diesel, produced from 2013 to 2017, represents a pinnacle of luxury and performance within the fourth generation of Audi’s flagship sedan. This variant, equipped with the potent 4.2-liter V8 diesel engine and an eight-speed Tiptronic automatic transmission, was positioned as a high-end offering, bridging the gap between the more accessible 3.0 TDI models and the ultra-exclusive 6.3-liter W12. The facelift brought updated styling, enhanced technology, and refinements to the already sophisticated A8 platform (based on the Volkswagen Group’s D4 architecture). It served as a key competitor to the BMW 7 Series and Mercedes-Benz S-Class in the full-size luxury segment, particularly in European and Asian markets.
Technical Specifications
| Brand | Audi |
| Model | A8 |
| Generation | A8 (D4,4H facelift 2013) |
| Type (Engine) | 4.2 TDI V8 clean diesel (385 Hp) quattro Tiptronic |
| Start of production | 2013 |
| End of production | 2017 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 9.4 l/100 km (25 US mpg, 30.1 UK mpg, 10.6 km/l) |
| Fuel consumption (extra urban) | 6.1 l/100 km (38.6 US mpg, 46.3 UK mpg, 16.4 km/l) |
| Fuel consumption (combined) | 7.4 l/100 km (31.8 US mpg, 38.2 UK mpg, 13.5 km/l) |
| CO2 emissions | 194 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 4.7 sec |
| Acceleration 0 – 62 mph | 4.7 sec |
| Acceleration 0 – 60 mph | 4.5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.3 kg/Hp, 188.7 Hp/tonne |
| Weight-to-torque ratio | 2.4 kg/Nm, 416.7 Nm/tonne |
| Power | 385 Hp @ 3750 rpm |
| Power per litre | 93.1 Hp/l |
| Torque | 850 Nm @ 2000-2750 rpm (626.93 lb.-ft. @ 2000-2750 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | CTEC |
| 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 | Turbocharger, Intercooler |
| 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 | 2040 kg (4497.43 lbs.) |
| Max. weight | 2705 kg (5963.5 lbs.) |
| Max load | 665 kg (1466.07 lbs.) |
| Trunk (boot) space – minimum | 490 l (17.3 cu. ft.) |
| Fuel tank capacity | 82 l (21.66 US gal, 18.04 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 | 5135 mm (202.17 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 | 1000 mm (39.37 in.) |
| Rear overhang | 1143 mm (45 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 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 | Electric Steering |
| Tires size | 235/55 R18 |
| Wheel rims size | 8J x 18 |
Powertrain & Engine Architecture
The heart of the A8 4.2 TDI is the CTEC engine, a 4.134-liter V8 diesel. This engine utilizes a common rail direct injection system, delivering fuel at extremely high pressures for optimized combustion. It’s equipped with a sequential turbocharger system – two turbochargers working in tandem to minimize turbo lag and maximize power across the rev range. The first, smaller turbocharger provides boost at lower engine speeds, while the second, larger turbocharger takes over at higher speeds. Intercooling further enhances performance by cooling the compressed intake air. The engine boasts 385 horsepower at 3750 rpm and a substantial 850 Nm (626.93 lb-ft) of torque between 2000 and 2750 rpm. This torque output is a key characteristic of modern diesel engines, providing effortless acceleration and strong pulling power. The eight-speed Tiptronic automatic transmission is designed to handle the engine’s significant torque. It offers both fully automatic operation and manual gear selection via steering wheel-mounted paddles or the gear selector lever.
Driving Characteristics
The 4.2 TDI A8 delivers a driving experience that blends effortless power with refined comfort. The abundant torque allows for brisk acceleration – 0 to 60 mph in approximately 4.5 seconds – and makes overtaking a breeze. The Tiptronic transmission shifts smoothly and responsively, although it isn’t as overtly sporty as some dual-clutch transmissions. The quattro all-wheel-drive system provides excellent traction in all weather conditions, enhancing stability and confidence. Compared to the 3.0 TDI models, the 4.2 TDI offers a noticeably more powerful and refined experience. While the 3.0 TDI provides adequate performance for most drivers, the 4.2 TDI caters to those who prioritize effortless power and a more luxurious feel. It’s also quicker and more capable than the petrol-powered variants.
Equipment & Trim Levels
The A8 4.2 TDI typically came well-equipped as standard. Features included leather upholstery, multi-zone climate control, a premium sound system, navigation, and a suite of driver-assistance systems such as adaptive cruise control, lane departure warning, and parking sensors. Optional extras included massaging seats, a rear-seat entertainment system, a panoramic sunroof, and advanced driver-assistance packages. Interior trim options ranged from wood veneers to aluminum accents, allowing buyers to personalize the cabin to their taste. The A8’s interior was renowned for its high-quality materials and meticulous craftsmanship.
Chassis & Braking
The A8’s chassis features an independent multi-link suspension at both the front and rear, providing a comfortable and controlled ride. The air suspension system, often included as standard or an option, further enhances ride quality by automatically adjusting the suspension damping to suit road conditions. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. The electronic stability control (ESC) system helps to maintain control during emergency maneuvers. The A8’s steering is precise and well-weighted, offering a good balance between comfort and responsiveness.
Market Reception & Comparison
The A8 4.2 TDI was generally well-received by automotive critics. It was praised for its powerful engine, refined ride, luxurious interior, and advanced technology. However, some critics noted that the fuel economy, while respectable for a vehicle of its size and performance, wasn’t as impressive as some of its competitors. Compared to the 3.0 TDI A8, the 4.2 TDI offered a significant performance upgrade but came at a higher price. It also tended to have slightly higher running costs due to the increased complexity of the engine and its associated components.
Legacy
The Audi A8 4.2 TDI (D4) has proven to be a relatively reliable vehicle, although, as with any complex luxury car, it’s not without its potential issues. Common maintenance items include regular oil changes, filter replacements, and inspection of the turbocharger system. The diesel particulate filter (DPF) can require periodic cleaning or replacement, particularly if the vehicle is primarily used for short trips. The Tiptronic transmission is generally robust, but proper fluid changes are essential for long-term reliability. On the used car market, the A8 4.2 TDI remains a desirable option for buyers seeking a luxurious and capable full-size sedan. Its combination of performance, comfort, and technology continues to appeal to discerning drivers.
