Triumph Stag vs Triumph Thunderbird: MOT reliability compared
Updated 05 September 2026.
10.7%
Triumph Thunderbird MOT failure rate, 11.9 pts lower than Triumph Stag
Triumph Thunderbird is the more reliable MOT performer: 10.7% of Triumph Thunderbird MOTs fail versus 22.6% for Triumph Stag, a 11.9 point gap.
| Metric | Triumph Stag | Triumph Thunderbird |
|---|---|---|
| MOT failure rate | 22.6% | 10.7% |
| Tests analysed | 87,808 | 81,236 |
| Most common failure | Lamps & electrical (40.6%) | Brakes (21.2%) |
Questions and answers
Which is more reliable, Triumph Stag or Triumph Thunderbird?
Triumph Thunderbird is the more reliable MOT performer: 10.7% of Triumph Thunderbird MOTs fail versus 22.6% for Triumph Stag, a 11.9 point gap.
What is the MOT failure rate of the Triumph Stag?
22.6% of Triumph Stag MOT tests result in a failure, from 87,808 tests.
What is the MOT failure rate of the Triumph Thunderbird?
10.7% of Triumph Thunderbird MOT tests result in a failure, from 81,236 tests.