Douglas Dragonfly vs Suzuki DR-Z400S

The Douglas Dragonfly passes its MOT first time more often than the Suzuki DR-Z400S: 93.6% vs 80.4%, a 13.2-point lead.

MOT reliability, side by side

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

Metric	Douglas Dragonfly	Suzuki DR-Z400S
First-time pass rate	93.6%	80.4%
Outright fail rate	2.4%	11.1%
Engine size	350cc	398cc
Rank among all models	#224 of 5428	#3493 of 5428
Median miles at test	8,174	6,940
MOT tests analysed	374	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.

Pass rate by test year

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

Test year	Douglas Dragonfly	Suzuki DR-Z400S
2006	93.2%	83.5%
2007	89.8%	83.1%
2008	95.9%	80.5%
2009	96.2%	78.2%
2010	94.4%	78.9%
2011	93.0%	78.3%
2012	90.9%	79.8%

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	Douglas Dragonfly	Suzuki DR-Z400S
0k-10k miles	93.2%	81.7%
10k-20k miles	97.8%	78.4%
20k-30k miles	97.0%	79.2%

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

DOUGLAS DRAGONFLY 93.6% pass · 374 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.