Ducati ST4S vs Suzuki GSF1200

The Ducati ST4S passes its MOT first time more often than the Suzuki GSF1200: 86.9% vs 82.4%, a 4.5-point lead.

MOT reliability, side by side

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

Metric	Ducati ST4S	Suzuki GSF1200
First-time pass rate	86.9%	82.4%
Outright fail rate	8.0%	8.9%
Vs comparable bikes (age & mileage adjusted)	+2.4 pts	-1.2 pts
Engine size	996cc	1,157cc
Rank among all models	#1937 of 5428	#3108 of 5428
Median miles at test	17,286	20,274
MOT tests analysed	5,237	97,637
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	Ducati ST4S	Suzuki GSF1200
Lights & signalling	3.6%	4.5%
Steering & suspension	2.9%	2.2%
Brakes	1.2%	2.8%
Tyres & wheels	1.2%	2.0%
Drive system	0.5%	0.6%
Fuel & exhaust	0.2%	0.8%
Structure & body	0.2%	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

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

Test year	Ducati ST4S	Suzuki GSF1200
2018	89.2%	83.2%
2019	94.4%	82.9%
2020	85.3%	83.4%
2021	86.7%	82.9%
2022	92.2%	83.6%
2023	86.7%	83.8%
2024	90.8%	83.4%
2025	83.6%	84.1%

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	Ducati ST4S	Suzuki GSF1200
0k-10k miles	89.6%	87.7%
10k-20k miles	85.3%	83.8%
20k-30k miles	88.1%	81.1%
30k-40k miles	86.0%	78.5%
40k-50k miles	82.6%	78.4%
50k-60k miles	89.8%	78.8%

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

Ducati ST4S vs Suzuki GSF1200 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ducati ST4S or the Suzuki GSF1200?

The Ducati ST4S passes its MOT first time more often than the Suzuki GSF1200: 86.9% vs 82.4%, a 4.5-point lead. Adjusted for age, mileage and test class, the Ducati ST4S still comes out ahead: +2.4 points vs comparable bikes for the Ducati ST4S, -1.2 for the Suzuki GSF1200. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ducati ST4S fail its MOT on most?

Lights & signalling: 3.6% of Ducati ST4S MOT tests failed on it, then steering & suspension (2.9%).

What does the Suzuki GSF1200 fail its MOT on most?

Lights & signalling: 4.5% of Suzuki GSF1200 MOT tests failed on it, then brakes (2.8%).

Which holds up better at high mileage, the Ducati ST4S or the Suzuki GSF1200?

At 50k-60k miles the Ducati ST4S passes first time more often: 89.8% for the Ducati ST4S vs 78.8% for the Suzuki GSF1200.

DUCATI ST4S 86.9% pass · 5,237 tests SUZUKI GSF1200 82.4% pass · 97.6k tests

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