2020-2025 · 2.0 TFSI EA888 (252 hp, later 265 hp) + electric motor (105 kW), 299 hp system output as the 50 TFSI e, 367 hp as the 55 TFSI e, quattro S tronic
The plug-in hybrid version of Audi's C8-generation executive saloon and Avant estate, pairing a 2.0 TFSI EA888 four-cylinder with a 105 kW electric motor integrated into the 7-speed S tronic gearbox. This report is written around the 50 TFSI e, the volume version with 220 kW / 299 hp of system output, and covers the 55 TFSI e launch variant alongside it, which is a separate derivative with 270 kW / 367 hp of system output. Both use quattro ultra all-wheel drive. The petrol engine itself is rated 185 kW / 252 hp on early cars and 195 kW / 265 hp on the later specification, so the 299 hp and 367 hp figures always describe petrol plus electric together, never the combustion engine alone. Launch cars (late 2019 / early 2020) carried a 14.1 kWh battery with approximately 50 km WLTP electric range; from early 2021 this grew to 17.9 kWh and around 73 km WLTP. The Avant estate body followed in 2021 and the TFSI e stayed in the C8 range until 2025. Hugely popular as a German company car thanks to the 0.5% BIK tax rate, meaning the used market is dominated by ex-fleet cars that were often driven on motorways without regular charging.· more· less
Strong combined output, smooth EV modeProven EA888 engine underneath
Two high-voltage battery recalls to verify by VINExpensive if never charged regularly
Buy if: You can charge daily and want a refined executive PHEV with quattro, and the car has documented charging history and verified recall completion.
Avoid if: You cannot charge regularly (fuel consumption rises to 8-10 l/100 km), want predictable running costs, or the battery recalls (93AB and 93AD) have not been completed.
High-voltage battery cell defect and capacity loss
€2,500 - 8,0001 of 7
Samsung SDI battery modules can develop cell defects; capacity degradation reduces electric range over time · more· less
The A6 TFSI e uses a Samsung SDI lithium-ion battery (14.1 kWh on 2020 models, 17.9 kWh from 2021). Recall 93AB (KBA reference 14586R) covers defective cell modules on 2021-2023 production cars that can overheat during charging, and the later European recall 93AD covers the same overheating-while-charging risk across A6, A7 and Q5 plug-in hybrids built between 1 August 2019 and 31 August 2024 (EU Safety Gate alert 10096643), so applicability has to be confirmed against the VIN. Beyond the recalls, gradual capacity loss is expected: real-world electric range typically drops 10-15% over the first 80,000 km. Cars that were rarely charged (common on ex-company cars) may show less degradation because the battery was cycled less, but may also have cells that drifted out of balance. Audi covers manufacturing defects in the HV battery for 8 years / 160,000 km (transferable to subsequent owners). Capacity retention is a separate, market-specific term rather than a Europe-wide promise: Audi UK offered 5 years / 100,000 miles to the first registered owner only, while Audi Italy limits capacity-loss cover to battery-electric cars and does not extend it to plug-in hybrids. Check what the country of first registration actually granted, and as a used buyer assume there is no capacity guarantee. Individual module replacement costs €2,500-4,000. A full battery pack replacement runs €6,000-8,000. Always request a battery health reading via OBDeleven or VCDS before purchase: state of health below 85% indicates significant degradation.
Onboard charger (AC charger) failure
€2,000 - 3,5002 of 7
The 7.4 kW onboard charger can fail, preventing all AC charging · more· less
The A6 TFSI e uses a 7.4 kW single-phase onboard charger to convert AC mains power to DC for the battery. This module can fail, triggering error messages such as 'Charging connector still attached' or 'Charging system fault' and preventing any plug-in charging. The car remains fully drivable on the petrol engine, but without charging, it runs as a heavy petrol car consuming 8-10 l/100 km. Some owners also report the charge port flap actuator sticking, which is a separate (cheaper) repair. The charger module itself (part number 5QE915681S) costs approximately €2,500. Including labour, total replacement runs €2,800-3,500 at an Audi dealer. Independent PHEV specialists may offer the repair for €2,000-2,500. This component is not covered by the HV battery warranty; it falls under the standard 2-year vehicle warranty only.
Coolant pump and thermostat housing failure
€800 - 1,5003 of 7
The EA888's belt-driven coolant pump and thermostat housing assembly leaks, typically between 60,000-100,000 km · more· less
A well-documented EA888 issue shared with the non-hybrid A6 C8 variants. The main coolant pump on this engine is not electric: it is driven by a toothed belt inside the engine and is built into a single assembly with the coolant regulator and thermostat housing, which uses plastic components that crack under thermal cycling. The small auxiliary electric pumps that circulate coolant for the hybrid and heating circuits are separate, much cheaper parts and should not be confused with it. On the PHEV, the engine runs intermittently as the hybrid system manages power, which can increase thermal stress compared to a car where the engine runs continuously. Symptoms include low coolant warnings, a sweet smell from the engine bay, and visible coolant weeping around the thermostat housing. A slipped or broken toothed belt for the pump shows up as overheating rather than a slow leak, so treat any temperature warning as urgent. Replacing the coolant pump and thermostat housing assembly costs €800-1,000 at an independent shop and €1,200-1,500 at an Audi dealer. Upgraded aluminium thermostat housings are available aftermarket.
12V auxiliary battery drain
€200 - 4004 of 7
PHEV electronic modules draw elevated standby current, draining the 12V battery within 5-7 days of inactivity · more· less
A widespread characteristic of all VW Group PHEVs. The hybrid control units, HV battery monitoring system, and telematics module draw more standby current than a conventional car. Owners report the 12V battery going flat within 5-7 days of inactivity, especially in cold weather. When the 12V battery is dead, the car cannot start even with a full HV battery, because the 12V system is needed to activate the contactors that connect the HV system. A software update improved the DC-DC converter management on some cars, allowing the HV battery to top up the 12V battery more effectively. A quality AGM replacement battery costs €200-300. Using a trickle charger (CTEK MXS 5.0 recommended) when the car is parked for more than a few days is the standard preventive measure.
Brake disc corrosion from low friction-brake use
€400 - 9005 of 7
Regenerative braking reduces mechanical brake use, leading to accelerated disc corrosion and pitting · more· less
PHEVs that are regularly driven in electric mode use regenerative braking for most deceleration. The mechanical brakes are applied infrequently, which means the disc surfaces are not cleaned by regular pad contact. This leads to a visible layer of surface rust that builds up rapidly, particularly in wet climates. While a thin rust layer is normal and clears with use, on PHEVs the corrosion can progress to deep pitting and uneven surfaces that cause vibration under braking. Brake pads typically last much longer on a PHEV (100,000+ km is common), but the discs may need replacing sooner than on a conventional car. Front disc and pad replacement costs €400-600. A full set (front and rear) runs €700-900. During any test drive, apply the brakes firmly from 80 km/h and check for vibration or pulsing.
Carbon buildup on intake valves
€500 - 1,0006 of 7
Direct injection means fuel does not wash the intake valves, allowing carbon deposits to accumulate · more· less
The EA888 uses direct injection exclusively, so no fuel passes over the intake valves to clean them. Over time, oil vapour from the crankcase ventilation system bakes onto the valve stems and ports, restricting airflow. On a PHEV, the engine's intermittent operation can make this worse: the engine may not reach full operating temperature on short runs before switching back to electric mode, reducing the combustion heat that would otherwise help burn off deposits. Symptoms include rough idle, hesitation on acceleration, and reduced power. A walnut-blasting service to clean the intake valves costs €400-600 at a specialist. A more thorough chemical clean with valve removal runs €700-1,000. Regular spirited driving to keep the engine hot helps slow the buildup. At 100,000 km, an inspection of the intake ports is recommended.
Hybrid S-tronic gearbox hesitation
€1,500 - 4,0007 of 7
The electrified 7-speed S tronic can exhibit jerky transitions between electric and combustion modes at low speeds · more· less
The A6 TFSI e uses an electrified variant of the DL382 7-speed dual-clutch S tronic, with the electric motor integrated between the engine and gearbox. During transitions between pure electric drive and engine engagement (especially at low speeds in traffic), some owners report a noticeable jolt or hesitation as the engine clutch engages. In most cases, software updates improve the calibration and resolve the issue. Hardware failures of the mechatronic unit are less common on the A6's DL382-based unit than on the smaller DQ400e used in the A3 and Golf PHEVs, because the DL382 uses a wet-clutch design. Specialist mechatronic repair costs €1,500-2,000. Full gearbox replacement at Audi runs €3,500-4,000. Fluid changes every 60,000 km are recommended but are not always performed by fleet operators.
Proven engine, but PHEV complexity adds costly potential repairs
The EA888 petrol engine at the core of the A6 TFSI e is well-proven across the Volkswagen Group. However, the plug-in hybrid system adds a complete high-voltage layer: battery, onboard charger, electric motor, dual cooling circuits, and modified gearbox. Two battery recalls must be checked against the VIN: 93AB on 2021-2023 production cars, and the wider European 93AD covering A6, A7 and Q5 plug-in hybrids built from 1 August 2019 to 31 August 2024. Ex-company cars that were rarely charged are common and may have degraded batteries, corroded brake discs, and carbon-fouled intake valves. Cars with documented regular charging and Audi service history are significantly lower risk. The 8-year HV battery defect warranty provides some protection, but capacity-retention cover is set market by market and, where it exists, applies to the first owner only, so a used buyer should not count on it.
Service history
Complete Audi dealer or VAG specialist records essential. Verify oil changes at the correct intervals and confirm S tronic fluid was changed at 60,000 km.
Tires
Check tread depth, age (date codes), and uneven wear patterns. PHEVs are heavier than non-hybrid equivalents, so tire wear can be faster.
Cold start (petrol engine)
Start the petrol engine cold. On a PHEV, this may require holding the 'EV' button or disabling auto-start. Listen for unusual rattling or rough idle.
Test drive
Drive for at least 25 minutes in both electric and hybrid modes, including motorway speeds. Test electric-to-petrol transitions at low speed.
Specific for this vehicle
Request HV battery health report
Use OBDeleven or VCDS to read battery state of health. Capacity below 85% indicates significant degradation. Check individual cell voltages for imbalance greater than 30 mV.
Test AC charging with a cable
Plug the car into a wallbox or EVSE and verify charging starts and progresses. Check the charge port flap opens and locks correctly. Watch for any error messages on the MMI.
Verify battery recall 93AB completion
Contact Audi with the VIN to confirm recall 93AB (KBA 14586R, Samsung SDI battery cell defect) has been completed on 2021-2023 production cars.
+ 6 more checksShow less
Verify battery recall 93AD completion
Ask Audi to check the VIN against recall 93AD, the European campaign for A6, A7 and Q5 plug-in hybrids built from 1 August 2019 to 31 August 2024 whose battery cell modules may overheat while charging (EU Safety Gate alert 10096643).
Inspect brake discs for corrosion and pitting
Visually check all four brake disc surfaces through the wheel spokes. Light surface rust is normal, but deep pitting or grooves require disc replacement.
Check coolant level and condition
With the engine cold, check the coolant expansion tank level and colour. Low level or discoloured fluid suggests a coolant pump or thermostat housing leak.
Verify the car was charged regularly
Ask about charging habits. An ex-company car with 80,000 km and a barely used battery may have sat depleted for months. Check the MMI charging statistics if available.
Check 12V battery voltage
Measure 12V battery voltage with the engine off (should be above 12.4V). Ask the seller if the car has needed jump-starts or if a trickle charger is used.
Test electric-to-engine transitions at low speed
Drive slowly in traffic or a car park and let the engine engage. Harsh jolts or hesitation during the transition suggest S tronic clutch or calibration issues.
Recalls and Technical Service Bulletins
High-voltage battery cell defect, fire risk during charging (KBA 14586R / Audi 93AB, 2021-2023 production, 44,059 vehicles)Critical - verify completed
High-voltage battery cell modules may overheat while charging (Audi 93AD, A6/A7/Q5 plug-in hybrids produced 1 August 2019 to 31 August 2024, EU Safety Gate alert 10096643)Verify with VIN
Contact Audi with the VIN to verify all recalls have been completed. The Samsung SDI battery recall (93AB) is critical: affected cars can overheat during charging. The later European recall 93AD covers the same charging overheat risk on A6, A7 and Q5 plug-in hybrids produced between 1 August 2019 and 31 August 2024, and applicability depends on the VIN, so ask Audi to check both. Audi monitors some vehicles remotely, but workshop inspection and potential module replacement may still be required.
Warranty Status
Factory warranty (2 years, no km limit)Expired on most used cars
HV battery defect warranty (8 years / 160,000 km)Covers manufacturing defects in the battery pack only. Transferable to subsequent owners.
HV battery capacity warranty (market-specific terms)Audi UK: 5 years / 100,000 miles, first owner only. Audi Italy covers capacity loss on battery-electric cars only, not plug-in hybrids.
Rust perforation warranty (12 years)May still apply on 2020+ cars
The HV battery warranty covers the battery pack itself against manufacturing defects for 8 years / 160,000 km and transfers to subsequent owners. Capacity retention is a separate promise and is set market by market rather than across Europe: Audi UK's term was 5 years / 100,000 miles and applied to the first registered owner only, while Audi Italy limits capacity-loss cover to battery-electric cars and does not offer it on plug-in hybrids. Check the published terms for the country of first registration, and as a used buyer assume there is no capacity cover at all. Audi will cover a battery that fails due to a manufacturing defect, but not one that has simply degraded. The onboard charger, electric motor, power electronics, and DC-DC converter are NOT covered by the battery warranty; they fall under the standard 2-year vehicle warranty.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
