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Daihatsu Opti vs Daihatsu Sirion: reliability comparison

MOT pass rates, common faults and mileage compared from real UK MOT data.

Daihatsu Opti
66%
MOT pass rate · 3 vehicles
Daihatsu Sirion
77%
MOT pass rate · 16,687 vehicles
Verdict: On MOT pass rate the Daihatsu Opti (66%) and Daihatsu Sirion (77%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Daihatsu Opti Daihatsu Sirion
MOT pass rate 66% 77% ✓
MOT failure rate 34% 23% ✓
Faults & advisories per test 3.2 1.8 ✓
Dangerous-fault share 1% 1%
Average mileage 103,505 mi 80,054 mi
Sample size (vehicles) 3 16,687

Most common faults

Daihatsu Opti

  1. Exhaust emissions carbon monoxide content after 2nd fast idle excessive (7.3.D.3)
  2. Nearside Front Anti-roll bar rubber bush deteriorated but not resulting in excessive movement (2.4.G.2)
  3. Play in steering rack inner joint(s)
  4. Offside Front Anti-roll bar rubber bush deteriorated but not resulting in excessive movement (2.4.G.2)
  5. Offside Rear Tyre worn close to the legal limit (4.1.E.1)
  6. Nearside Rear Tyre worn close to the legal limit (4.1.E.1)

Daihatsu Sirion

  1. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  2. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  3. Front Brake pad(s) wearing thin (3.5.1g)
  4. Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
  5. Offside Rear Brake pipe corroded, covered in grease or other material (1.1.11 (c))
  6. Front brake disc worn, pitted or scored, but not seriously weakened (3.5.1i)

Reliability FAQ

On MOT pass rate the Daihatsu Opti (66%) and Daihatsu Sirion (77%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Daihatsu Opti report Full Daihatsu Sirion 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.