Mercedes C Class vs Tesla Model 3
Take the Mercedes C Class for lower age-adjusted MOT risk: its index is 83.6 versus 122.9 for the Tesla Model 3, and the 95% confidence intervals do not overlap.
Lower is better. The index adjusts for each fleet's exact age profile; the raw failure rate below does not. The index gap is 39.3 points. Data release dvsa-2024-v1.
Side-by-side evidence
| Measure | Mercedes C Class | Tesla Model 3 |
|---|---|---|
| Age-adjusted MOT Risk Index | 83.6 (83.2–84.0) | 122.9 (121.2–124.7) |
| Raw initial failure rate | 22.55% | 14.03% |
| Dangerous defects per 100 tests | 15.68 | 18.40 |
| Initial tests | 646,907 | 116,025 |
Where their MOT failures diverge
These are component groups present in both models' published top-six failure lists, sorted by the absolute gap. A positive difference means the Mercedes C Class records more failure items; a negative one means the Tesla Model 3 does.
| Component group | Mercedes C Class | Tesla Model 3 | Difference | Lower rate |
|---|---|---|---|---|
| Suspension | 27.5 | 3.0 | +24.5 pp | Tesla Model 3 |
| Brakes | 14.1 | 0.9 | +13.2 pp | Tesla Model 3 |
| Lamps, reflectors and electrical equipment | 12.7 | 2.7 | +10.0 pp | Tesla Model 3 |
| Tyres | 13.4 | 21.8 | -8.4 pp | Mercedes C Class |
| Visibility | 11.2 | 4.4 | +6.8 pp | Tesla Model 3 |
Counts are defect items, not the share of cars: one failed test can contain several items. A group absent from a model's top six is not treated as zero.
What the six-year test history says
The longitudinal layer follows the same vehicles between MOTs from 2019 to 2024. It separates a one-day retest from the harder question of what returns next year, and puts failures against miles actually driven.
| Component | Mercedes C Class | Tesla Model 3 | Difference | Tracked advisories |
|---|---|---|---|---|
| Suspension | 23.8% | 6.5% | +17.3 pp | 178,319 / 1,890 |
| Brakes | 11.7% | 1.7% | +10.0 pp | 334,639 / 3,755 |
| Tyres | 10.0% | 11.3% | -1.4 pp | 385,864 / 11,597 |
| Non-component advisories | 0.0% | 0.0% | 0.0 pp | 76,886 / 1,887 |
| Measure | Mercedes C Class | Tesla Model 3 |
|---|---|---|
| Repaired and passed the same day | 39.0% | 41.3% |
| Passed 1–10 days later | 57.5% | 54.9% |
| Median retest delay | 1.0 days | 1.0 days |
| Failures per 10,000 miles | 0.340 | 0.145 |
| Three-test clean streak | 38.4% | 34.0% |
| Same advisory repeated 3+ times | 27.0% | 4.6% |
Care proxy is descriptive, not a claim about an owner's character: a clean streak means three or more consecutive tests with nothing recorded; the repeat measure means the same advisory appeared at least three times.
Safety recalls
| Model | Campaigns listed | Per 10,000 licensed |
|---|---|---|
| Mercedes C Class | 158 | 4.86 |
| Tesla Model 3 | 11 | 0.80 |
More campaigns do not by themselves mean a less reliable car: recalls are manufacturer remedies, and the licensed-fleet denominator is unavailable for some families. Check a registration for outstanding work before buying.
Do other countries see the same thing?
Both models appear in the same independent national inspection datasets below. Compare each model with that country's own average; absolute pass rates are not portable between rulebooks.
| Country / test | Model | Model fails | National average | Position | Inspections |
|---|---|---|---|---|---|
| Netherlands · APK | Mercedes C Class | 48.4% | 50.9% | -2.5 pp | 47,418 |
| Netherlands · APK | Tesla Model 3 | 45.5% | 50.9% | -5.4 pp | 9,985 |
| Norway · PKK | Mercedes C Class | 35.6% | 33.5% | +2.1 pp | 4,363 |
| Norway · PKK | Tesla Model 3 | 27.9% | 33.5% | -5.6 pp | 1,715 |
Sources are the national PKK, Katsastus and APK datasets recorded in each family artifact. Position is model failure rate minus that country's national rate.
Quick answers
- Is the Mercedes C Class or the Tesla Model 3 more reliable?
- The Mercedes C Class has the stronger age-adjusted MOT result: index 83.6 against 122.9 for the Tesla Model 3, with non-overlapping 95% confidence intervals.
- Does the Mercedes C Class or the Tesla Model 3 fail more MOTs?
- 22.55% of Mercedes C Class initial tests and 14.03% of Tesla Model 3 initial tests found a failing defect in 2024. The lower raw rate belongs to the Tesla Model 3, but the age-adjusted index is the fairer model comparison because the fleets can be different ages.
- What are the main MOT problem areas on the Mercedes C Class and Tesla Model 3?
- The leading published failure group for the Mercedes C Class is suspension at 27.5 items per 100 tests; for the Tesla Model 3 it is tyres at 21.8 per 100.
- Should I buy a Mercedes C Class or a Tesla Model 3?
- If MOT reliability is the deciding factor, the Mercedes C Class is the evidence-led choice. Still check the individual car's MOT history and condition: these figures describe whole model populations, not a particular vehicle.
Model pages and nearby comparisons
See the Mercedes A Class and Volkswagen Golf comparisonSee the MINI Hatch and Toyota Yaris comparisonSee the Mercedes A Class and Vauxhall Astra comparison
Browse all car reliability comparisons.
How to read and cite this comparison
Scope: class-4 vehicles, initial tests only, Great Britain 2024. PRS fixed-on-the-spot results count as failures because a defect was present on arrival. Index = observed initial failures ÷ age-profile-expected failures × 100; intervals are 95% confidence intervals. Every model family combines all generations and engines. Full method: methodology.
Cite: MOT Risk Index (2026). Mercedes C Class vs Tesla Model 3: MOT reliability comparison, 2024 (dvsa-2024-v1). https://motriskindex.co.uk/compare/mercedes-c-class-vs-tesla-model-3/