Audi A8 D4 vs Audi A8 D5: which is more reliable?
According to the MotorFiable Score, the Audi A8 D4 and the Audi A8 D5 are tied (6.6/10): the differences lie in which systems fail, not how much.
| Item | Audi A8 D4 | Audi A8 D5 |
|---|---|---|
| Segment | Saloon | Saloon |
| Years | 2010–2017 | 2017–today |
| MotorFiable Score | 6.6 out of 10 | 6.6 out of 10 |
| Engine score | 5.8/10 | 5.2/10 |
| Most recommended engine | Audi 3.0 TFSI V6 · With caution | Audi 3.0 TFSI V6 · Buy |
| Score for the rest of the car | 7.4/10 | 8.0/10 |
| Suspension | 8.4 out of 101 faultHigh severity | 8.3 out of 102 faultsHigh severity |
| Gearbox and clutch | No documented faults | 9.3 out of 101 faultMedium severity |
| Electrical system | No documented faults | 9.3 out of 101 faultMedium severity |
| Electronics and infotainment | 9.6 out of 101 faultLow severity | No documented faults |
| Bodywork and interior | 8.1 out of 101 faultHigh severity | 7.7 out of 100 faults |
| Airbags and safety | 8.6 out of 101 faultCritical severity | 8.9 out of 101 faultHigh severity |
Scores out of 10: the higher, the fewer serious documented faults. How we calculate them
Main faults of the Audi A8 D4
Outside the engine
- High severityFrequency: OccasionalSuspensionLeaks in the air suspension and failure of the compressor or height sensorsA buyer's guide notes bellows that sag or leak, and compressors or height sensors that fail with age, on A8 D4s with adaptive air suspension.
- Critical severityFrequency: RareAirbags and safetyIncorrect mixture in airbag and pretensioner initiators (production from July to December 2016)Audi recalled A8s (and A1, A4, A5, A6, A7, Q5, Q7) built between July and December 2016 because a difference in the mixture of the initiators could prevent airbags or pretensioners from deploying.
- High severityFrequency: RareBodywork and interiorGlass sunroof that can break (A8 built from March to July 2013)Audi recalled A8s built between March and July 2013 because the glass sunroof could suddenly shatter into small pieces, posing an accident risk.
In their engines
- High severityFrequency: Common3.0 TDI V6Failing water pump and cooling system leaksOn the 3.0 TDI the water pump can fail and, from 2010, overheat to the point of damaging the engine (the A6 C6 guide cites a service action). Owners also cite coolant leaks from hoses, the regulating valve and the cooler.
- High severityFrequency: Occasional3.0 TDI V6Timing chain stretch and tensioner wearOn the 3.0 TDI V6 the timing chain is at the gearbox end and its tensioner can lose tension: it rattles on a cold start and, if the chain stretches, the timing goes out and the engine is at risk. Replacing it means opening the engine and costs several thousand euros.
- High severityFrequency: Occasional3.0 TDI V6Injector wear (needle seat) and injection faultsGerman guides point to wear of the needle seat of the 3.0 TDI injectors: they stop closing properly, diesel drips into the cylinder and dilutes the oil. Smoke from the exhaust can be the warning, and reports on the 313 hp twin-turbo repeat injection faults.
Main faults of the Audi A8 D5
Outside the engine
- Medium severityFrequency: OccasionalSuspensionRear axle arm nuts and wheel alignment and camber readjustmentAudi recalled A8s built between 7 November 2019 and 16 April 2021 because the eccentric bolt nuts on a rear axle arm could crack through stress corrosion. A second campaign corrected alignment and camber problems that appeared after the first.
- High severityFrequency: RareSuspensionSuspension arms with a manufacturing defect (2018, 2019 and 2024 campaigns)There are three campaigns for the A8 D5's suspension parts: a component that could break (produced November-December 2018), faulty rear wishbones (17 to 25 October 2019) and a front arm with cracks (2024-2025 model years).
- High severityFrequency: RareAirbags and safetyAirbag impact sensors incorrectly fitted in the front doorsAudi recalled A8s built between July and September 2020 because defective impact sensors may have been fitted in both front doors, which could reduce the action of the side, curtain and pretensioner airbags.
In their engines
- High severityFrequency: Common3.0 TDI V6Failing water pump and cooling system leaksOn the 3.0 TDI the water pump can fail and, from 2010, overheat to the point of damaging the engine (the A6 C6 guide cites a service action). Owners also cite coolant leaks from hoses, the regulating valve and the cooler.
- High severityFrequency: Occasional3.0 TDI V6Timing chain stretch and tensioner wearOn the 3.0 TDI V6 the timing chain is at the gearbox end and its tensioner can lose tension: it rattles on a cold start and, if the chain stretches, the timing goes out and the engine is at risk. Replacing it means opening the engine and costs several thousand euros.
- High severityFrequency: Occasional3.0 TDI V6Injector wear (needle seat) and injection faultsGerman guides point to wear of the needle seat of the 3.0 TDI injectors: they stop closing properly, diesel drips into the cylinder and dilutes the oil. Smoke from the exhaust can be the warning, and reports on the 313 hp twin-turbo repeat injection faults.