Data as of: DVSA MOT results to 2025
KTM 390 vs Suzuki DR-Z400S
The KTM 390 passes its MOT first time more often than the Suzuki DR-Z400S: 86.4% vs 80.4%, a 6.0-point lead.
MOT reliability, side by side
| Metric | KTM 390 | Suzuki DR-Z400S |
|---|---|---|
| First-time pass rate | 86.4% | 80.4% |
| Outright fail rate | 7.2% | 11.1% |
| Vs comparable bikes (age & mileage adjusted) | -2.0 pts | -6.5 pts |
| Engine size | 373cc | 398cc |
| Rank among all models | #2091 of 5428 | #3493 of 5428 |
| Median miles at test | 5,598 | 6,940 |
| MOT tests analysed | 3,737 | 26,773 |
| Most common failure | lamps and reflectors | lighting and signalling |
First-time outcomes on normal tests, 2005–2025. "Most common failure" is the component group with the most recorded defects on failed tests. Read pass rates against test counts: a smaller sample is noisier. Source: DVSA anonymised MOT results.
"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.
What fails, side by side
| Component | KTM 390 | Suzuki DR-Z400S |
|---|---|---|
| Lights & signalling | 3.0% | 6.1% |
| Brakes | 2.0% | 3.5% |
| Steering & suspension | 1.4% | 3.2% |
| Tyres & wheels | 1.5% | 2.6% |
| Structure & body | 2.1% | 0.7% |
| Drive system | 0.1% | 0.8% |
| Fuel & exhaust | 0.0% | 0.6% |
A test that fails on two components counts once in each. Component links go to the bikes most likely to fail on it.
Pass rate by test year
| Test year | KTM 390 | Suzuki DR-Z400S |
|---|---|---|
| 2018 | 85.7% | 79.5% |
| 2019 | 86.4% | 82.2% |
| 2020 | 86.9% | 80.0% |
| 2021 | 86.1% | 83.4% |
| 2022 | 87.7% | 81.8% |
| 2023 | 86.6% | 84.9% |
| 2024 | 85.9% | 84.3% |
| 2025 | 86.8% | 83.7% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | KTM 390 | Suzuki DR-Z400S |
|---|---|---|
| 0k-10k miles | 87.8% | 81.7% |
| 10k-20k miles | 82.0% | 78.4% |
| 20k-30k miles | 78.9% | 79.2% |
Bands with fewer than 30 tests for either bike are left out.
KTM 390 vs Suzuki DR-Z400S FAQ
Which is more reliable, the KTM 390 or the Suzuki DR-Z400S?
The KTM 390 passes its MOT first time more often than the Suzuki DR-Z400S: 86.4% vs 80.4%, a 6.0-point lead. Adjusted for age, mileage and test class, the KTM 390 still comes out ahead: -2.0 points vs comparable bikes for the KTM 390, -6.5 for the Suzuki DR-Z400S. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the KTM 390 fail its MOT on most?
Lights & signalling: 3.0% of KTM 390 MOT tests failed on it, then structure & body (2.1%).
What does the Suzuki DR-Z400S fail its MOT on most?
Lights & signalling: 6.1% of Suzuki DR-Z400S MOT tests failed on it, then brakes (3.5%).
Which holds up better at high mileage, the KTM 390 or the Suzuki DR-Z400S?
They are level: at 20k-30k miles the KTM 390 passes 78.9% first time and the Suzuki DR-Z400S 79.2%.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.