Where each one leads
BMW M5
- Against cars of the same age, the BMW M5 comes out better at its first MOT test (passes 31% more often than average) than the Mercedes-Benz S-Class (passes 16% more often than average).
- Against cars of the same year, the BMW M5 comes out better in New York safety inspections (fails 71% less often than average) than the Mercedes-Benz S-Class (fails 64% less often than average).
- Fewer BMW M5 cars in the Netherlands carry an illogical odometer record (2.1% against 8.2%).
- Measured by the cars' own fuel meters, the petrol BMW M5 uses 14.2 l/100 km on the road, the Mercedes-Benz S-Class 15.6.
Mercedes-Benz S-Class
- New Mercedes-Benz S-Class cars registered in Europe in 2022 average 165 g/km of CO₂ on the WLTP test, against 255 for the BMW M5 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
| BMW M5 | Mercedes-Benz S-Class | |
|---|---|---|
| Model years in the US safety record | 1989–2026 | 1994–2012 |
| New cars registered in Europe | 15,353 (2010–2022) | 136,729 (2010–2022) |
| Licensed in the United Kingdom | 6,139 | 22,797 |
| On the road in the Netherlands | 2,326 | 8,416 |
| In traffic in Finland | 276 | 2,778 |
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
| BMW M5 | Mercedes-Benz S-Class | |
|---|---|---|
| UK MOT first-time pass rate | 86% | 83% |
| … against cars of the same age | +31% | +16% |
| New York safety inspections failed | 0.4% | 0.6% |
| … against cars of the same year | −71% | −64% |
| Illogical odometer records (NL) | 2.1% | 8.2% |
| US owner complaints | 106 | 271 |
| Most complaints about | Air bags | Electrical system |
| Model year with most complaints | 2006 (39) | 2000 (81) |
| US recall campaigns | 23 | 11 |
| Manufacturer service bulletins | 2,339 | 116 |
| NHTSA defect investigations | 3 | 7 |
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
| BMW M5 | Mercedes-Benz S-Class | |
|---|---|---|
| Official combined fuel use, Canada | 13.8 l/100 km (2023) | — |
| Real-world use in Europe, petrol | 14.2 l/100 km | 15.6 l/100 km |
| Real-world use in Europe, diesel | — | 8.8 l/100 km |
| Real-world use in Europe, petrol hybrid | — | 11.9 l/100 km |
| Real-world use in Europe, diesel hybrid | — | 8.2 l/100 km |
| Official CO₂ of new cars in Europe | 255 g/km | 165 g/km |
| Average power of new cars in Europe | 458 kW (614 hp) | 290 kW (389 hp) |
| Average mass in running order | 1,975 kg | 2,204 kg |
| Dutch list price when new (median) | €157,514 | €142,880 |
| Average odometer in Finland | 167,000 km | 226,000 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).