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Triumph T20s vs Triumph Unknown: reliability comparison

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

Triumph T20s
85%
MOT pass rate · 5 vehicles
Triumph Unknown
89%
MOT pass rate · 65,927 vehicles
Verdict: On MOT pass rate the Triumph T20s (85%) and Triumph Unknown (89%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Triumph T20s Triumph Unknown
MOT pass rate 85% 89% ✓
MOT failure rate 15% 11% ✓
Faults & advisories per test 0.4 ✓ 0.6
Dangerous-fault share 0% ✓ 2%
Average mileage 441 mi 16,601 mi
Sample size (vehicles) 5 65,927

Most common faults

Triumph T20s

  1. Steering movement slightly stiff (2.2.1b)
  2. Front Roller brake test indicates a slightly juddering brake (3.3.A1b)
  3. Rear wheel bearings have slight free play (2.4.A.2c)
  4. Stop lamp does not illuminate immediately a brake applies (1.3.1a)
  5. Front wheel bearings are excessively rough (2.3.5b)
  6. Roller brake test The less effective brake control does not achieve an efficiency of 25%. (3.3.A2b)

Triumph Unknown

  1. Exhaust noisy (8.1.1 (a))
  2. Exhaust noisy (7.1.2)
  3. Front Roller brake test indicates slight fluctuation of brake effort (3.3.A1d)
  4. COVID-19 6 MONTH EXTENSION
  5. Rear Tyre worn close to the legal limit (5.2.3 (e))
  6. Steering headbearing has slight free play (2.2.2)

Reliability FAQ

On MOT pass rate the Triumph T20s (85%) and Triumph Unknown (89%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Triumph T20s report Full Triumph Unknown 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.