Where each one leads
Audi A5
- Fewer Audi A5 cars in the Netherlands carry an illogical odometer record (2.7% against 9.5%).
Mercedes-Benz SLK
- Against cars of the same age, the Mercedes-Benz SLK comes out better at its first MOT test (passes 16% more often than average) than the Audi A5 (passes 8% more often than average).
- On Canada's official test the most frugal 2016 Mercedes-Benz SLK uses 8.5 l/100 km, the 2026 Audi A5 9.1.
- New Mercedes-Benz SLK cars registered in Europe in 2020 average 153 g/km of CO₂ on the WLTP test, against 167 for the Audi A5 in 2022.
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 A5 | Mercedes-Benz SLK | |
|---|---|---|
| Model years in the US safety record | 2008–2026 | 1998–2012 |
| New cars registered in Europe | 265,785 (2010–2022) | 75,551 (2010–2020) |
| Licensed in the United Kingdom | 130,463 | 47,128 |
| On the road in the Netherlands | 6,562 | 9,739 |
| In traffic in Finland | 2,687 | 2,181 |
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 A5 | Mercedes-Benz SLK | |
|---|---|---|
| UK MOT first-time pass rate | 79% | 73% |
| … against cars of the same age | +8% | +16% |
| New York safety inspections failed | 1.0% | — |
| … against cars of the same year | −45% | — |
| Illogical odometer records (NL) | 2.7% | 9.5% |
| US owner complaints | 325 | 74 |
| Most complaints about | Electrical system | Visibility |
| Model year with most complaints | 2020 (60) | 2002 (25) |
| US recall campaigns | 19 | 3 |
| Manufacturer service bulletins | 13,501 | 79 |
| NHTSA defect investigations | — | 9 |
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).
Fuel, emissions and price
| Audi A5 | Mercedes-Benz SLK | |
|---|---|---|
| Official combined fuel use, Canada | 9.1 l/100 km (2026) | 8.5 l/100 km (2016) |
| Real-world use in Europe, diesel hybrid | 6.9 l/100 km | — |
| Real-world use in Europe, petrol hybrid | 8.3 l/100 km | — |
| Real-world use in Europe, diesel | 6.5 l/100 km | — |
| Official CO₂ of new cars in Europe | 167 g/km | 153 g/km |
| Average power of new cars in Europe | 165 kW (221 hp) | 120 kW (161 hp) |
| Average mass in running order | 1,715 kg | 1,578 kg |
| Dutch list price when new (median) | €63,628 | €61,479 |
| Average odometer in Finland | 250,000 km | 175,000 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).