All generations and engines together · 17,327 MOT tests in the 2025 data · typical mileage at age 7: 64k
Worse than most coupés and convertibles, by age and by mileage. Watch brakes and wheels. A used buy worth some caution. Check the MOT history for repeating brakes advisories before you go.
Split by first-registration year. Cars registered in a changeover year can belong to either generation.
Owner folklore from forums and the motoring press, with how well each report stands up. Most of it never shows up in an MOT, which is why this section exists at all.
Pre-facelift CLS (roughly 2003 to 2006) used Sensotronic Brake Control, an electro-hydraulic brake-by-wire system rather than a conventional master cylinder. A failing unit shows up as a brake warning light, a pedal that feels inconsistent or oddly firm, or the car dropping back onto its backup hydraulic circuit. Mercedes recalled hundreds of thousands of SBC cars in 2004 and 2005, and in 2018 extended the warranty on the SBC pump, control unit and sensors to 25 years with no mileage limit, which tells you how long these can take to fail and how costly they are to fix. It is the clearest owner-folklore version of this model's measured 'brakes' fault, though the measured data covers all CLS generations, not only SBC cars.
CLS350 and CLS500/550 petrol models from roughly 2004 to 2007 use the M272 V6 or M273 V8 engine, both prone to premature wear of the balance shaft sprockets. The tell is a rattle or knock on cold start that gradually worsens and doesn't fully settle once warm, usually appearing from about 60,000 to 80,000 miles, often just after warranty cover has run out. The fix means stripping the front of the engine and is a four-figure job. Mercedes never issued a UK recall for it but settled two US class actions over the fault, including a 2015 settlement covering part of the repair cost on 2005 to 2007 cars.
Every CLS generation has offered Airmatic air suspension, and the struts, compressor and valve block all wear with age rather than failing for one single reason. Signs are a corner of the car sitting low overnight, a compressor that seems to run constantly trying to hold pressure, or a suspension warning message on the dash. Owners argue over whether this is a genuine CLS weak spot or simply what any ageing air-sprung car does, but either way a full set of struts plus a new compressor is a big bill, so budget for it on any car past 80,000 miles or so.
CLS electrics run through front and rear SAM (signal acquisition module) boards, a known weak point across the wider Mercedes range. A faulty board can send the wrong signals between the two units, so owners report interior lights staying on, warning lights with no obvious cause, or a battery that's flat by morning. One reported case was a 2016 CLS 350d with under 10,000 miles on the clock, where independent diagnosis plus parts came to close to £1,000. It isn't manufacturer-acknowledged as a design fault, so it gets treated as ordinary, if expensive, electrical wear.
CLS250 CDI models from around 2012 were covered by an injector replacement recall. Some owners who had the work done reported noticeably worse fuel economy afterwards, which suggests the original injectors were already close to the edge of their tolerances before they were changed. It's a diesel-only issue and doesn't touch the petrol V6 or V8 cars.
A batch of CLS built around 2014 to 2016, including the Shooting Brake, were recalled over a loose seal in the secondary bulkhead that could contact the engine and create a fire risk. Owners also reported a burning smell from the rear of the car that dealers initially dismissed, before, in a handful of cases, an actual fire followed. Check that any car from these years has had the recall work carried out, and get proof of it in the history file.
Ranked from this model’s own MOT record, then from what owners report.
Saveable checklistThe physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
The physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
Drawn from the reports above rather than the MOT data. These are the model-specific ones.
Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.
Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.
The rows that judge the model rather than its keeper. 6,534 tests in this band.
Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.
Same segment (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.