Aprilia SX vs Piaggio NRG

The Piaggio NRG passes its MOT first time more often than the Aprilia SX: 65.5% vs 64.1%, a 1.4-point lead.

MOT reliability, side by side

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

Metric	Aprilia SX	Piaggio NRG
First-time pass rate	64.1%	65.5%
Outright fail rate	25.3%	27.4%
Vs comparable bikes (age & mileage adjusted)	-9.2 pts	-6.0 pts
Engine size	50cc	49cc
Rank among all models	#5054 of 5428	#4992 of 5428
Median miles at test	7,978	9,874
MOT tests analysed	1,366	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.

What fails, side by side

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

Component	Aprilia SX	Piaggio NRG
Lights & signalling	18.1%	15.0%
Steering & suspension	10.2%	15.5%
Brakes	8.9%	10.2%
Structure & body	9.2%	2.5%
Tyres & wheels	2.4%	4.7%
Fuel & exhaust	0.1%	3.8%
Drive system	0.8%	0.0%

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	Aprilia SX	Piaggio NRG
2018	64.0%	69.2%
2019	60.3%	68.0%
2020	72.1%	71.8%
2021	64.2%	72.9%
2022	63.9%	74.8%
2023	63.4%	77.5%
2024	58.2%	81.9%
2025	64.3%	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	Aprilia SX	Piaggio NRG
0k-10k miles	66.1%	71.3%
10k-20k miles	58.4%	60.6%
20k-30k miles	62.1%	55.7%

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

Aprilia SX vs Piaggio NRG FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Aprilia SX or the Piaggio NRG?

The Piaggio NRG passes its MOT first time more often than the Aprilia SX: 65.5% vs 64.1%, a 1.4-point lead. Adjusted for age, mileage and test class, the Piaggio NRG still comes out ahead: -9.2 points vs comparable bikes for the Aprilia SX, -6.0 for the Piaggio NRG. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Aprilia SX fail its MOT on most?

Lights & signalling: 18.1% of Aprilia SX MOT tests failed on it, then steering & suspension (10.2%).

What does the Piaggio NRG fail its MOT on most?

Steering & suspension: 15.5% of Piaggio NRG MOT tests failed on it, then lights & signalling (15.0%).

Which holds up better at high mileage, the Aprilia SX or the Piaggio NRG?

At 20k-30k miles the Aprilia SX passes first time more often: 62.1% for the Aprilia SX vs 55.7% for the Piaggio NRG.

APRILIA SX 64.1% pass · 1,366 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.