Ajs 18S: MOT pass rate by registration year

Which 18S years pass first time, and which fall short of the model's 92.8% average, from 598 DVSA tests.

1953

highest-passing year · 98.9%

1955

lowest-passing year · 92.3%

6.6pp

spread across 5 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: 1953 (98.9% of 89 tests). Lowest: 1955 (92.3% of 91).

Registered	Tests	First-time pass	vs model (92.8%)
1952	80	95.0%	+2.2 pp
1953	89	98.9%	+6.1 pp
1954	58	94.8%	+2.0 pp
1955	91	92.3%	-0.5 pp
1957	65	96.9%	+4.1 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 · 2006–2012

Questions

Which 18S years have the lowest MOT pass rate?: none: no registration year of the Ajs 18S falls more than two points under the model's 92.8% overall pass rate.
Which 18S year has the highest MOT pass rate?: 1953, at 98.9% of 89 first tests (2005–2025). Years more than two points above the model average: 1952, 1953, 1957.
How much does the 18S pass rate vary by year?: 6.6 percentage points between the highest (1953, 98.9%) and lowest (1955, 92.3%) 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: Ajs 18S reliability, failures and mileage · ranked #330 of 5428 models· other Ajs models: Modena, Modena 125, DD, Firefox, DD 125 E 08, 16MS