Lambretta LI150 Special: MOT pass rate by registration year

Which LI150 Special years pass first time, and which fall short of the model's 90.4% average, from 1,091 DVSA tests.

1964

highest-passing year · 93.4%

1965

lowest-passing year · 87.9%

5.5pp

spread across 4 years

Pass rate by registration year

first-time pass rate · cohorts with 50 or more tests · registration year from first use date

Highest pass rate: 1964 (93.4% of 349 tests). Lowest: 1965 (87.9% of 231). Years more than two points below the model average: 1963, 1965.

Registered	Tests	First-time pass	vs model (90.4%)
1963	102	88.2%	-2.2 pp
1964	349	93.4%	+3.0 pp
1965	231	87.9%	-2.5 pp
1966	190	91.1%	+0.7 pp

Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years. A first-time MOT pass is a roadworthiness check, not a full mechanical inspection.

Pass rate over time

first-time pass rate by test year · 2006–2018

Questions

Which LI150 Special years have the lowest MOT pass rate?: 1963, 1965 registered examples pass first time less often than the Lambretta LI150 Special overall (90.4%); the 1965 cohort is lowest at 87.9% from 231 tests.
Which LI150 Special year has the highest MOT pass rate?: 1964, at 93.4% of 349 first tests (2005–2025).
How much does the LI150 Special pass rate vary by year?: 5.5 percentage points between the highest (1964, 93.4%) and lowest (1965, 87.9%) cohorts with at least 50 tests. Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years.

Full report: Lambretta LI150 Special reliability, failures and mileage · ranked #825 of 5428 models· other Lambretta models: LI125, GP200, LI150, GP150, GP125, Li