2023 Mercedes-Benz S-Class — MOT failures & pass rate
Across 766 MOT tests, the 2023 Mercedes-Benz S-Class recorded a 95.0% pass rate. Executive cars of a similar age fail at 5.3%, so the 2023 S-Class sits squarely on the average. Failures cluster in tyres, lighting & signalling and brakes.
What the MOT record shows
Tyres dominates the failure mix at 4.8% of all tests — 4.6 points clear of lighting & signalling, so it is the first thing to check.
At component level the recurring items are tread depth, headlamp aim and brake pads — tread depth alone was recorded 5 times.
Mileage is the strongest signal on the record: 4.1% of 0-30k cars fail, rising to 9.5% once past 60-90k — 2.3× the risk.
Advisories point at the next bill rather than this one: tyres was flagged on 11.0% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 4.8% | 37 |
| 2 | Lighting & signalling | 0.3% | 2 |
| 3 | Brakes | 0.3% | 2 |
| 4 | Road wheels | 0.1% | 1 |
| 5 | Visibility | 0.1% | 1 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 5 |
| 2 | Headlamp aim | 3 |
| 3 | Brake pads | 2 |
| 4 | Size/type | 2 |
| 5 | Tyre pressure monitoring system | 1 |
| 6 | Attachment | 1 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 11.0% | 84 |
| 2 | Brakes | 2.2% | 17 |
| 3 | Other defects | 1.2% | 9 |
| 4 | Visibility | 0.7% | 5 |
| 5 | Suspension | 0.3% | 2 |
| 6 | Body, structure & corrosion | 0.1% | 1 |
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 | 392 | 4.1% |
| 30-60k | 286 | 4.9% |
| 60-90k | 74 | 9.5% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Hybrid | 662 | 4.8% |
| Diesel | 104 | 5.8% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2024 | 312 | 6.1% |
| 2025 | 438 | 4.3% |
What to check before buying a 2023 S-Class
On a 2023 S-Class, tyres is what the MOT record says goes wrong most — it appeared in 4.8% of tests. Check these areas before you commit.
- Tyres (4.8% 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.
- Lighting & signalling (0.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (0.3% 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 2023 Mercedes-Benz S-Classs pass their MOT?
95.0% of the 766 2023 Mercedes-Benz S-Class MOT tests in this dataset passed — a 5.0% fail rate.
What is the most common MOT failure on a 2023 Mercedes-Benz S-Class?
Tyres, recorded in 4.8% of tests, followed by lighting & signalling (0.3%).
Does the 2023 S-Class get worse with mileage?
Its MOT fail rate rises from 4.1% in the 0-30k band to 9.5% in the 60-90k band.
Methodology & source. Based on 766 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.