Vespa (douglas) PK vs Piaggio NRG

The Vespa (douglas) PK passes its MOT first time more often than the Piaggio NRG: 75.5% vs 65.5%, a 10.0-point lead.

MOT reliability, side by side

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

Metric	Vespa (douglas) PK	Piaggio NRG
First-time pass rate	75.5%	65.5%
Outright fail rate	18.4%	27.4%
Vs comparable bikes (age & mileage adjusted)	-4.4 pts	-6.0 pts
Engine size	50cc	49cc
Rank among all models	#4245 of 5428	#4992 of 5428
Median miles at test	10,305	9,874
MOT tests analysed	277	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 mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Vespa (douglas) PK	Piaggio NRG
0k-10k miles	75.0%	71.3%
10k-20k miles	78.6%	60.6%
20k-30k miles	71.7%	55.7%

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

VESPA (DOUGLAS) PK 75.5% pass · 277 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.