Yamaha YQ 50 Aero vs Piaggio NRG

The Piaggio NRG passes its MOT first time more often than the Yamaha YQ 50 Aero: 65.5% vs 51.1%, a 14.4-point lead.

MOT reliability, side by side

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

Metric	Yamaha YQ 50 Aero	Piaggio NRG
First-time pass rate	51.1%	65.5%
Outright fail rate	35.5%	27.4%
Vs comparable bikes (age & mileage adjusted)	-19.8 pts	-6.0 pts
Engine size	49cc	49cc
Median miles at test	10,247	9,874
MOT tests analysed	186	40,458
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.

Pass rate by test year

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

Test year	Yamaha YQ 50 Aero	Piaggio NRG
2006	44.4%	64.7%
2007	67.5%	63.9%
2008	46.8%	65.2%

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	Yamaha YQ 50 Aero	Piaggio NRG
0k-10k miles	50.5%	71.3%
10k-20k miles	51.2%	60.6%

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

YAMAHA YQ 50 AERO 51.1% pass · 186 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.