Mash Fifty vs Piaggio NRG

The Mash Fifty passes its MOT first time more often than the Piaggio NRG: 71.3% vs 65.5%, a 5.8-point lead.

MOT reliability, side by side

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

Metric	Mash Fifty	Piaggio NRG
First-time pass rate	71.3%	65.5%
Outright fail rate	16.8%	27.4%
Vs comparable bikes (age & mileage adjusted)	-6.7 pts	-6.0 pts
Engine size	49cc	49cc
Rank among all models	#4631 of 5428	#4992 of 5428
Median miles at test	4,430	9,874
MOT tests analysed	345	40,458
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.

Pass rate by test year

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

Test year	Mash Fifty	Piaggio NRG
2020	81.4%	71.8%
2021	61.5%	72.9%
2022	78.9%	74.8%
2023	76.1%	77.5%
2024	71.9%	81.9%
2025	61.0%	77.1%

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	Mash Fifty	Piaggio NRG
0k-10k miles	70.0%	71.3%
10k-20k miles	63.6%	60.6%

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

MASH FIFTY 71.3% pass · 345 tests PIAGGIO NRG 65.5% pass · 40.5k tests

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