KTM 400 Exc vs Suzuki DR-Z400S

The Suzuki DR-Z400S passes its MOT first time more often than the KTM 400 Exc: 80.4% vs 77.3%, a 3.1-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	KTM 400 Exc	Suzuki DR-Z400S
First-time pass rate	77.3%	80.4%
Outright fail rate	12.1%	11.1%
Vs comparable bikes (age & mileage adjusted)	-11.4 pts	-6.5 pts
Engine size	400cc	398cc
Rank among all models	#4013 of 5428	#3493 of 5428
Median miles at test	3,637	6,940
MOT tests analysed	5,086	26,773
Most common failure	lighting and signalling	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

share of each bike's MOT tests that failed on the component · lower is better

Component	KTM 400 Exc	Suzuki DR-Z400S
Lights & signalling	7.7%	6.1%
Steering & suspension	5.4%	3.2%
Brakes	2.1%	3.5%
Tyres & wheels	2.6%	2.6%
Drive system	0.6%	0.8%
Structure & body	0.6%	0.7%
Fuel & exhaust	0.3%	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

first-time MOT pass rate in each calendar year both bikes were tested

Test year	KTM 400 Exc	Suzuki DR-Z400S
2018	82.1%	79.5%
2019	80.6%	82.2%
2020	84.7%	80.0%
2021	79.8%	83.4%
2022	77.2%	81.8%
2023	79.7%	84.9%
2024	84.3%	84.3%
2025	77.1%	83.7%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test

Mileage	KTM 400 Exc	Suzuki DR-Z400S
0k-10k miles	77.1%	81.7%
10k-20k miles	81.3%	78.4%

Bands with fewer than 30 tests for either bike are left out.

KTM 400 Exc vs Suzuki DR-Z400S FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the KTM 400 Exc or the Suzuki DR-Z400S?

The Suzuki DR-Z400S passes its MOT first time more often than the KTM 400 Exc: 80.4% vs 77.3%, a 3.1-point lead. Adjusted for age, mileage and test class, the Suzuki DR-Z400S still comes out ahead: -11.4 points vs comparable bikes for the KTM 400 Exc, -6.5 for the Suzuki DR-Z400S. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the KTM 400 Exc fail its MOT on most?

Lights & signalling: 7.7% of KTM 400 Exc MOT tests failed on it, then steering & suspension (5.4%).

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%).

KTM 400 EXC 77.3% pass · 5,086 tests SUZUKI DR-Z400S 80.4% pass · 26.8k tests

See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.