Data as of: DVSA MOT results to 2025
Royal Enfield Bullet Classic Efi E4 vs Kawasaki ZX-6R
The Royal Enfield Bullet Classic Efi E4 passes its MOT first time more often than the Kawasaki ZX-6R: 89.9% vs 78.1%, a 11.8-point lead.
MOT reliability, side by side
| Metric | Royal Enfield Bullet Classic Efi E4 | Kawasaki ZX-6R |
|---|---|---|
| First-time pass rate | 89.9% | 78.1% |
| Outright fail rate | 4.7% | 14.0% |
| Vs comparable bikes (age & mileage adjusted) | +0.2 pts | -5.8 pts |
| Engine size | 499cc | 599cc |
| Rank among all models | #988 of 5428 | #3895 of 5428 |
| Median miles at test | 3,494 | 19,446 |
| MOT tests analysed | 3,550 | 173,956 |
| 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 | Royal Enfield Bullet Classic Efi E4 | Kawasaki ZX-6R |
|---|---|---|
| Lights & signalling | 2.2% | 6.1% |
| Brakes | 1.1% | 5.2% |
| Steering & suspension | 0.6% | 4.6% |
| Tyres & wheels | 1.0% | 3.6% |
| Structure & body | 0.8% | 1.2% |
| Drive system | 0% | 1.0% |
| Fuel & exhaust | 0% | 0.8% |
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 | Royal Enfield Bullet Classic Efi E4 | Kawasaki ZX-6R |
|---|---|---|
| 2020 | 96.1% | 78.1% |
| 2021 | 88.3% | 78.6% |
| 2022 | 88.2% | 79.4% |
| 2023 | 88.7% | 79.8% |
| 2024 | 91.2% | 80.3% |
| 2025 | 91.0% | 81.1% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Royal Enfield Bullet Classic Efi E4 | Kawasaki ZX-6R |
|---|---|---|
| 0k-10k miles | 90.3% | 86.1% |
| 10k-20k miles | 84.0% | 80.6% |
| 20k-30k miles | 88.2% | 75.4% |
Bands with fewer than 30 tests for either bike are left out.
Royal Enfield Bullet Classic Efi E4 vs Kawasaki ZX-6R FAQ
Which is more reliable, the Royal Enfield Bullet Classic Efi E4 or the Kawasaki ZX-6R?
The Royal Enfield Bullet Classic Efi E4 passes its MOT first time more often than the Kawasaki ZX-6R: 89.9% vs 78.1%, a 11.8-point lead. Adjusted for age, mileage and test class, the Royal Enfield Bullet Classic Efi E4 still comes out ahead: +0.2 points vs comparable bikes for the Royal Enfield Bullet Classic Efi E4, -5.8 for the Kawasaki ZX-6R. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Royal Enfield Bullet Classic Efi E4 fail its MOT on most?
Lights & signalling: 2.2% of Royal Enfield Bullet Classic Efi E4 MOT tests failed on it, then brakes (1.1%).
What does the Kawasaki ZX-6R fail its MOT on most?
Lights & signalling: 6.1% of Kawasaki ZX-6R MOT tests failed on it, then brakes (5.2%).
Which holds up better at high mileage, the Royal Enfield Bullet Classic Efi E4 or the Kawasaki ZX-6R?
At 20k-30k miles the Royal Enfield Bullet Classic Efi E4 passes first time more often: 88.2% for the Royal Enfield Bullet Classic Efi E4 vs 75.4% for the Kawasaki ZX-6R.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.