Where each one leads
Audi A6
- On Canada's official test the most frugal 2026 Audi A6 uses 10.2 l/100 km, the 2015 Mercedes-Benz CLS 13.1.
- New Audi A6 cars registered in Europe in 2022 average 131 g/km of CO₂ on the WLTP test, against 199 for the Mercedes-Benz CLS in 2022.
Mercedes-Benz CLS
Ahead on none of the like-for-like measures.
Too close to call: MOT pass rate against cars of the same age.
Only measures that do not depend on how many cars were sold: pass and failure rates against cars of the same age, ratings, fuel use and CO₂. How we compare
At a glance
| Audi A6 | Mercedes-Benz CLS | |
|---|---|---|
| Model years in the US safety record | 1994–2026 | 2006–2012 |
| New cars registered in Europe | 411,334 (2010–2022) | 2,712 (2011–2022) |
| Licensed in the United Kingdom | 129,627 | — |
| On the road in the Netherlands | 17,710 | — |
| In traffic in Finland | 12,113 | — |
EEA new-car registrations (CC BY 4.0) · DVLA licensed vehicles (OGL v3.0) · RDW (CC0) · Traficom (CC BY 4.0) · generations: Wikidata (CC0).
Reliability and problems
| Audi A6 | Mercedes-Benz CLS | |
|---|---|---|
| UK MOT first-time pass rate | 79% | 75% |
| … against cars of the same age | +11% | +9% |
| New York safety inspections failed | 1.2% | — |
| … against cars of the same year | −32% | — |
| Illogical odometer records (NL) | 4.2% | — |
| US owner complaints | 1,662 | 5 |
| Most complaints about | Electrical system | Fuel system, gasoline |
| Model year with most complaints | 1999 (217) | 2006 (3) |
| US recall campaigns | 54 | 1 |
| Manufacturer service bulletins | 17,761 | 64 |
| NHTSA defect investigations | 26 | 5 |
Complaint, recall and bulletin counts grow with the number of cars sold and are not adjusted for it. UK MOT: DVSA anonymised MOT results (OGL v3.0); New York: DMV inspections; complaints, recalls, bulletins and investigations: NHTSA (public domain); odometer: RDW (CC0).
Safety
| Audi A6 | Mercedes-Benz CLS | |
|---|---|---|
| NHTSA overall rating | 5★ (2021) | — |
NHTSA New Car Assessment Program, most recent rated model year (public domain).
Fuel, emissions and price
| Audi A6 | Mercedes-Benz CLS | |
|---|---|---|
| Official combined fuel use, Canada | 10.2 l/100 km (2026) | 13.1 l/100 km (2015) |
| Real-world use in Europe, diesel hybrid | 6.9 l/100 km | — |
| Real-world use in Europe, petrol hybrid | 9.2 l/100 km | — |
| Real-world use in Europe, diesel | 6.7 l/100 km | — |
| Official CO₂ of new cars in Europe | 131 g/km | 199 g/km |
| Average power of new cars in Europe | 174 kW (233 hp) | 249 kW (334 hp) |
| Average mass in running order | 1,842 kg | 1,926 kg |
| Dutch list price when new (median) | €71,765 | — |
| Average odometer in Finland | 285,000 km | — |
Canada: NRCan Fuel Consumption Ratings, most frugal version of the latest year (OGL Canada). Europe: EEA monitoring of new-car CO₂ and on-board fuel meters (OBFCM), CC BY 4.0. Price: RDW catalogue price (CC0). Finland: Traficom (CC BY 4.0).