2012 Mercedes-Benz CLS — MOT failures & pass rate
6,940 MOT tests on the 2012 Mercedes-Benz CLS are in this dataset, and 80.8% of them passed. Executive cars of a similar age fail at 18.3%, so the 2012 CLS sits squarely on the average. Failures cluster in tyres, suspension and brakes.
What the MOT record shows
No single area dominates — tyres (8.3%) and suspension (7.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are rigid brake pipes, coil spring and tread depth — rigid brake pipes alone was recorded 392 times.
Condition tracks the odometer closely. Failures run at 10.3% in the 0-30k band and 21.1% in the 150k+ band, a 10.7-point spread — more than double.
Split by fuel, diesel examples fail 4.9pp more often than petrol ones (19.7% vs 14.8%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: brakes was flagged on 30.7% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.3% | 577 |
| 2 | Suspension | 7.8% | 538 |
| 3 | Brakes | 5.6% | 390 |
| 4 | Lighting & signalling | 2.8% | 192 |
| 5 | Emissions & environmental | 2.5% | 175 |
| 6 | Visibility | 1.1% | 76 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 392 |
| 2 | Coil spring | 348 |
| 3 | Tread depth | 262 |
| 4 | Malfunction indicator lamp | 126 |
| 5 | Linkage ball joint dust cover | 125 |
| 6 | Headlamp aim | 117 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 30.7% | 2,132 |
| 2 | Tyres | 25.2% | 1,746 |
| 3 | Suspension | 16.3% | 1,129 |
| 4 | Other defects | 4.9% | 340 |
| 5 | Emissions & environmental | 4.7% | 329 |
| 6 | Visibility | 3.3% | 227 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 145 | 10.3% |
| 30-60k | 1,073 | 14.7% |
| 60-90k | 2,296 | 19.6% |
| 90-120k | 2,062 | 20.1% |
| 120-150k | 886 | 21.8% |
| 150k+ | 475 | 21.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 6,270 | 19.7% |
| Petrol | 670 | 14.8% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,472 | 18.6% |
| 2022 | 1,442 | 18.9% |
| 2023 | 1,398 | 19.0% |
| 2024 | 1,350 | 19.9% |
| 2025 | 1,278 | 19.6% |
What to check before buying a 2012 CLS
On a 2012 CLS, tyres is what the MOT record says goes wrong most — it appeared in 8.3% of tests. Check these areas before you commit.
- Tyres (8.3% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Suspension (7.8% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Brakes (5.6% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2012 Mercedes-Benz CLSs pass their MOT?
80.8% of the 6,940 2012 Mercedes-Benz CLS MOT tests in this dataset passed — a 19.2% fail rate.
What is the most common MOT failure on a 2012 Mercedes-Benz CLS?
Tyres, recorded in 8.3% of tests, followed by suspension (7.8%).
Does the 2012 CLS get worse with mileage?
Its MOT fail rate rises from 10.3% in the 0-30k band to 21.1% in the 150k+ band.
Methodology & source. Based on 6,940 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.