Ford Fiesta vs Ford Mercury: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Ford Fiesta
73%
MOT pass rate · 2,835,744 vehicles
Ford Mercury
79%
MOT pass rate · 87 vehicles
More reliable
Verdict: On MOT pass rate, the Ford Mercury is the more reliable of the two — 79% pass first time versus 73%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Ford Fiesta | Ford Mercury |
|---|---|---|
| MOT pass rate | 73% | 79% ✓ |
| MOT failure rate | 27% | 21% ✓ |
| Faults & advisories per test | 2.1 | 1.8 ✓ |
| Dangerous-fault share | 2% | 1% ✓ |
| Average mileage | 84,529 mi | 73,824 mi |
| Sample size (vehicles) | 2,835,744 | 87 |
Most common faults
Ford Fiesta
- Nearside Front Tyre worn close to the legal limit (4.1.E.1)
- Offside Front Tyre worn close to the legal limit (4.1.E.1)
- Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
- Offside Rear Brake pipe slightly corroded (3.6.B.2c)
Ford Mercury
- Oil leak
- Steering system has slight free play detected at steering wheel (2.2.A.1a)
- Parking brake: efficiency below requirements (3.7.B.7)
- Offside Rear Tyre slightly damaged/cracking or perishing (5.2.3 (d) (ii))
- Front Exhaust has a minor leak of exhaust gases (7.1.2)
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
Reliability FAQ
On MOT pass rate, the Ford Mercury is the more reliable of the two — 79% pass first time versus 73%. It's one signal among several; check the full breakdown below.
Full Ford Fiesta report Full Ford Mercury report Most reliable cars
Pass rates are computed over completed (pass/fail) MOT tests. Reliability also depends on age, mileage and upkeep — see each model's page for the full picture.