Triumph Unknown Reliability, MOT Pass Rate & Common Faults
Free Triumph Unknown car check
Is the Triumph Unknown reliable? We analysed 3,763 real MOT tests across 2,269 vehicles to find out.
Got a specific Triumph Unknown? Enter the reg for a free check:
The Triumph Unknown is above average for reliability based on real UK MOT data. Common problems include shock absorber seal failed and leaking oil, stop lamp does not illuminate immediately a brake applies and direction indicators not working. Here's everything you need to know before buying a used Triumph Unknown.
Triumph Unknown Number Plates
Number plates registered to a Triumph Unknown. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Triumph Unknown MOT Pass Rate by Year
How likely is a Triumph Unknown to pass its MOT? Here's the pass rate for each registration year, newest first.
Triumph Unknown Problems — What Goes Wrong?
The most common reasons a Triumph Unknown fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Triumph Unknown Common Faults & Problems
These are the most common serious faults found on Triumph Unknown models during MOT testing — flagged as dangerous or major failures that need immediate attention.
Triumph Unknown Mileage — What's Normal?
How many miles does a typical Triumph Unknown owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Triumph Unknown MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Triumph Unknown year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 2020 | 55 | 98.2% | 1,747 | 5,140 | 7,699 |
| 2019 | 97 | 92.8% | 3,980 | 6,474 | 9,665 |
| 2017 | 54 | 98.1% | 3,143 | 5,640 | 9,702 |
| 2016 | 73 | 93.2% | 3,474 | 8,100 | 14,088 |
| 2015 | 77 | 87.0% | 1,160 | 5,493 | 14,808 |
| 1996 | 138 | 79.7% | 6,277 | 15,602 | 23,565 |
| 1995 | 120 | 85.8% | 3,848 | 7,928 | 15,530 |
| 1994 | 113 | 82.3% | 8,890 | 14,998 | 28,487 |
| 1993 | 171 | 83.6% | 12,412 | 18,897 | 29,088 |
| 1992 | 92 | 83.7% | 5,726 | 16,437 | 33,730 |
| 1991 | 77 | 90.9% | 4,374 | 17,909 | 33,916 |
| 1982 | 64 | 92.2% | 5,218 | 8,532 | 19,029 |
| 1981 | 103 | 87.4% | 7,834 | 15,626 | 24,306 |
| 1980 | 141 | 88.7% | 4,432 | 14,372 | 27,387 |
| 1979 | 107 | 90.7% | 8,166 | 15,634 | 28,170 |
| 1978 | 131 | 88.5% | 2,619 | 13,782 | 25,319 |
| 1977 | 107 | 89.7% | 6,048 | 13,328 | 25,279 |
| 1976 | 87 | 85.1% | 3,538 | 12,992 | 26,492 |
| 1975 | 120 | 84.2% | 8,920 | 17,472 | 37,766 |
| 1974 | 59 | 91.5% | 2,955 | 17,429 | 31,769 |
How Long Does a Triumph Unknown Last?
Based on 2,269 Triumph Unknown vehicles on UK roads.
Triumph Unknown Mileage Distribution
Total mileage recorded across all Triumph Unknown MOT tests. If the car you're looking at is above the 75th percentile, it's done more miles than most.
Best Year to Buy a Used Triumph Unknown
Based on MOT pass rates across all registration years with sufficient test data.
98.4% MOT pass rate from 61 tests
79.7% MOT pass rate from 138 tests
The best year to buy a used Triumph Unknown is 1968, which has the highest MOT pass rate at 98.4% across 61 tests. The 1996 model year has the lowest pass rate at 79.7% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the Triumph Unknown Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Triumph Unknown THIS CAR | 88.8% | 3,763 | 11,023 mi | 66 yrs |
| Triumph Bonneville | 90.1% | 235,206 | 7,823 mi | 53 yrs |
| Triumph Tiger | 90.6% | 196,853 | 17,026 mi | 32 yrs |
| Triumph Sprint | 87.3% | 158,613 | 21,242 mi | 33 yrs |
| BMW K100 | 86.6% | 1,884 | 52,809 mi | 42 yrs |
Compared to the Triumph Bonneville (90.1% pass rate) and the Triumph Tiger (90.6% pass rate), the Triumph Unknown trails behind on MOT reliability.
Found a Triumph Unknown you like?
Run a full vehicle history check on the specific car. See finance, stolen, write-off, mileage and MOT data for that exact vehicle.
Check a specific Triumph UnknownShould you buy a used Triumph Unknown?
The Triumph Unknown has an overall MOT pass rate of 88.8% across 3,763 real MOT tests — comfortably above the UK average, which puts it among the more reliable models on UK roads.
The most common problems on the Triumph Unknown are shock absorber seal failed and leaking oil (13 recorded failures), stop lamp does not illuminate immediately a brake applies (13), and direction indicators not working (6). These are the faults most likely to cause an MOT failure on this model, so check for them carefully on any test drive or pre-purchase inspection. Many are wear-and-tear items that can be budgeted for, but a car that's already failing on multiple fronts may signal neglected maintenance.
On the safety side, the most frequently flagged dangerous fault is brake has no recorded effort at a wheel. Dangerous faults cause an immediate MOT failure and mean the vehicle is not roadworthy until repaired. If you're viewing a Triumph Unknown with an expired or recently passed MOT, ask the seller whether any dangerous faults were found and fixed during the last test.
A typical Triumph Unknown owner drives around 286 miles per year. If the car you're looking at is significantly above this, expect more wear on suspension, brakes and tyres. If it's well below, the vehicle may have been sitting unused — check for perished rubber, corroded discs and stale fluids.
In terms of longevity, most Triumph Unknown models stay on UK roads for around 66 years — a strong showing that suggests solid build quality and readily available parts. If you're buying one that's already approaching that window, the data suggests it has plenty of life left provided it's been maintained.
Before committing to a purchase, we recommend running a full vehicle history check on the specific car. This will reveal any outstanding finance, stolen markers, write-off history and mileage discrepancies that the seller may not disclose — and that the MOT data alone can't tell you.