2021 Audi A6 quattro — Full Specifications
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The 2021 Audi A6 quattro is a saloon/sedan offered with 2 engines (2L 4-cyl turbo, 3L 6-cyl turbo). Its most fuel-efficient configuration returns around 31 mpg (UK) / 26 mpg (US EPA) combined, with 29–31 mpg (UK) across all configurations. Owners often keep a Audi A6 quattro workshop manual to hand for servicing and repairs.
Compared with the 2020 Audi A6 quattro: Fuel economy is essentially unchanged at around 31 mpg (UK) combined. The engine line-up listed by EPA is unchanged. It carries the same 5★ overall NHTSA rating.
Full Specifications
| Engine (most efficient) | 2L 4-cyl turbo |
|---|---|
| Engine options | 2L 4-cyl turbo · 3L 6-cyl turbo |
| Transmission (most efficient) | Automatic (AM-S7) |
| Fuel Type | Premium Gasoline |
| Powertrain | Hybrid |
| Drive | All-Wheel Drive |
| Body Style | Saloon/Sedan |
| Passenger Volume (EPA) | 99 cu ft (2,803 L) |
| Luggage Volume (EPA) | 14 cu ft (396 L) |
| Fuel Economy (UK) | 31 combined / 28 urban / 37 extra-urban mpg |
| Fuel Economy (US EPA) | 26 combined / 23 city / 31 highway mpg |
| CO₂ Emissions | 212 g/km |
| EPA Greenhouse Gas Score | 5 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,150 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2021 Audi A6 quattro across 2 engines (2L 4-cyl turbo, 3L 6-cyl turbo). Combined fuel economy ranges from 24 to 26 mpg (US), or 29 to 31 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 2L 4-cyl turbo (Hybrid) | Automatic (AM-S7) | All-Wheel Drive | 31 | 26 (23/31) | 212 | $3,150 |
| 3L 6-cyl turbo (Hybrid) | Automatic (AM-S7) | All-Wheel Drive | 29 | 24 (22/29) | 226 | $3,400 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
EPA measures interior passenger volume at 99 cubic feet (about 2,803 litres) and luggage volume at 14 cubic feet (about 396 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2021 Audi A6 quattro
Running Costs: 2021 Audi A6 quattro
Covering around 8,000 miles a year in a 2021 Audi A6 quattro at 31 mpg combined, expect roughly 1,173 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,150 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Only need this car occasionally? See our buy vs rent comparison.
2021 Audi A6 quattro Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 11 safety recall campaigns that include the 2021 Audi A6 quattro (as of 6 October 2026). Most affected areas: Electrical system (4), Back over prevention (2), Service brakes (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Back over prevention — campaign 25V900000, reported 19 December 2025. Risk: A rearview image that does not display reduces the driver's view behind the vehicle, increasing the risk of a crash.
- Electrical system — campaign 25V201000, reported 31 March 2025. Risk: An instrument panel display that fails to show critical safety information, such as the speedometer or warning lights, increases the risk of a crash.
- Service brakes — campaign 23V601000, reported 25 August 2023. Risk: Incorrect brake fluid can reduce braking ability and increase the risk of a crash.
- Electrical system — campaign 22V861000, reported 21 November 2022. Risk: A gateway control module shutdown will suddenly reduce engine power, increasing the risk of a crash.
Showing the 4 most recent of 11 campaigns.
Owners have filed 17 complaints with NHTSA about the 2021 Audi A6 quattro. The most-reported areas are Electrical system (11), Engine (3), Unspecified (2). That is close to the median of 21 complaints across the 14 Audi A6 quattro model years in our data.
Used-buyer checklist for the 2021 Audi A6 quattro
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Electrical system (4 recall campaigns · 11 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Brakes (1 recall campaign) — Brake firmly from speed and look for pulling, vibration or a soft pedal; ask for brake service history.
- Tyres (1 recall campaign) — Check tyre age and wear and ask about any tyre recalls.
- Engine (3 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
Audi models in our database average about 27 mpg (UK) combined on their most efficient configuration; the 2021 Audi A6 quattro's 31 mpg is 4 mpg above that make average. Its 212 g/km CO₂ figure is 39 g/km lower than the 251 g/km Audi average.
Of the 16 Audi A6 quattro model years we cover, the 2021 ranks 7th for combined fuel economy on its best configuration (31 mpg UK combined, against a high of 36 mpg). See every Audi A6 quattro year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2021 Audi A6 quattro
Frequently Asked Questions
What engine does the 2021 Audi A6 quattro have?
EPA lists 2 engines for the 2021 Audi A6 quattro: 2L 4-cyl turbo, 3L 6-cyl turbo. The most fuel-efficient configuration pairs the 2L 4-cyl turbo with a automatic (am-s7).
What is the fuel economy of the 2021 Audi A6 quattro?
The most efficient configuration returns around 31 mpg (UK) combined, or 26 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 29 to 31 mpg.
How much does the 2021 Audi A6 quattro cost to fuel per year?
The US EPA estimates about $3,150 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2021 Audi A6 quattro have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 4 stars for frontal crash protection.
Does the 2021 Audi A6 quattro have any recalls?
NHTSA lists 11 safety recall campaigns that include the 2021 Audi A6 quattro (as of 6 October 2026). Most affected areas: Electrical system (4), Back over prevention (2), Service brakes (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
What are the most common problems reported for the 2021 Audi A6 quattro?
Among the 17 owner complaints filed with NHTSA, the most-reported areas are Electrical system (11 complaints), Engine (3 complaints), Unspecified (2 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
How much interior and luggage space does the 2021 Audi A6 quattro have?
EPA measures interior passenger volume at 99 cubic feet (about 2,803 litres) and luggage volume at 14 cubic feet (about 396 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.