1978 Triumph Stag — MOT History by Age

How cars manufactured in 1978 perform at MOT as they age

48 years

Current Age

73.1%

Latest Pass Rate

1,546

Total Tests (All Years)

65,460 mi

Avg Mileage (Latest)

Data from official DVSA MOT testing records

Insufficient data for same-age comparison.

How This Car Ages

Pass rate progression for the 1978 Triumph Stag as it ages.

31 yrs64.4%

→ ↓1.1%

32 yrs63.3%

→ ↑6.8%

33 yrs70.1%

→ ↓6.2%

34 yrs63.9%

→ ↑4.0%

35 yrs67.9%

→ ↓6.3%

36 yrs61.6%

→ ↑4.8%

37 yrs66.4%

→ ↑2.3%

38 yrs68.7%

→ ↑5.8%

39 yrs74.5%

→ ↑1.8%

40 yrs76.3%

→ ↓17.2%

41 yrs59.1%

→ ↑9.3%

43 yrs68.4%

→ ↑12.1%

45 yrs80.5%

→ ↓7.4%

46 yrs73.1%

📊 View as table

Age	Pass Rate	Tests
31 yrs	64.4%	146
32 yrs	63.3%	147
33 yrs	70.1%	144
34 yrs	63.9%	133
35 yrs	67.9%	140
36 yrs	61.6%	151
37 yrs	66.4%	146
38 yrs	68.7%	147
39 yrs	74.5%	141
40 yrs	76.3%	76
41 yrs	59.1%	44
43 yrs	68.4%	38
45 yrs	80.5%	41
46 yrs	73.1%	52

Pass Rate Trend

How the 1978 Triumph Stag pass rate changes as it ages, from first MOT to most recent.

📊 View as table

Built	Pass Rate	Tests
2024 (46 yrs)	73.1%	52
2023 (45 yrs)	80.5%	41
2021 (43 yrs)	68.4%	38
2019 (41 yrs)	59.1%	44
2018 (40 yrs)	76.3%	76
2017 (39 yrs)	74.5%	141
2016 (38 yrs)	68.7%	147
2015 (37 yrs)	66.4%	146
2014 (36 yrs)	61.6%	151
2013 (35 yrs)	67.9%	140
2012 (34 yrs)	63.9%	133
2011 (33 yrs)	70.1%	144
2010 (32 yrs)	63.3%	147
2009 (31 yrs)	64.4%	146

Year-by-Year MOT Results

2009High Fail Rate

64.4%

Age (yrs) 31Tests 146Avg Mileage 54,062Top Failure Suspension — 17.8%

2010High Fail Rate

63.3%

Age (yrs) 32Tests 147Avg Mileage 59,627Top Failure Lamps, Reflectors and Electrical Equipment — 19.0%

2011

70.1%

Age (yrs) 33Tests 144Avg Mileage 58,460Top Failure Lamps, Reflectors and Electrical Equipment — 15.3%

2012High Fail Rate

63.9%

Age (yrs) 34Tests 133Avg Mileage 55,904Top Failure Suspension — 19.5%

2013

67.9%

Age (yrs) 35Tests 140Avg Mileage 53,370Top Failure Suspension — 45.7%

2014High Fail Rate

61.6%

Age (yrs) 36Tests 151Avg Mileage 59,381Top Failure Lamps, Reflectors and Electrical Equipment — 55.6%

2015

66.4%

Age (yrs) 37Tests 146Avg Mileage 54,712Top Failure Lamps, Reflectors and Electrical Equipment — 33.6%

2016

68.7%

Age (yrs) 38Tests 147Avg Mileage 55,591Top Failure Suspension — 40.1%

2017

74.5%

Age (yrs) 39Tests 141Avg Mileage 55,728Top Failure Suspension — 31.2%

2018

76.3%

Age (yrs) 40Tests 76Avg Mileage 57,197Top Failure Brakes — 17.1%

2019High Fail Rate

59.1%

Age (yrs) 41Tests 44Avg Mileage 52,447Top Failure Lamps, reflectors and electrical equipment — 50.0%

2021

68.4%

Age (yrs) 43Tests 38Avg Mileage 54,855Top Failure Brakes — 44.7%

2023

80.5%

Age (yrs) 45Tests 41Avg Mileage 60,437Top Failure Lamps, reflectors and electrical equipment — 17.1%

2024

73.1%

Age (yrs) 46Tests 52Avg Mileage 65,460Top Failure Lamps, reflectors and electrical equipment — 30.8%

MOT results for 1978 Triumph Stag by test year
Test Year▲	Age (yrs)▲▼	Pass Rate▲▼	Tests▲▼	Avg Mileage▲▼	Top Failure▲▼
2009	31	64.4%	146	54,062	Suspension — 17.8%
2010	32	63.3%	147	59,627	Lamps, Reflectors and Electrical Equipment — 19.0%
2011	33	70.1%	144	58,460	Lamps, Reflectors and Electrical Equipment — 15.3%
2012	34	63.9%	133	55,904	Suspension — 19.5%
2013	35	67.9%	140	53,370	Suspension — 45.7%
2014	36	61.6%	151	59,381	Lamps, Reflectors and Electrical Equipment — 55.6%
2015	37	66.4%	146	54,712	Lamps, Reflectors and Electrical Equipment — 33.6%
2016	38	68.7%	147	55,591	Suspension — 40.1%
2017	39	74.5%	141	55,728	Suspension — 31.2%
2018	40	76.3%	76	57,197	Brakes — 17.1%
2019	41	59.1%	44	52,447	Lamps, reflectors and electrical equipment — 50.0%
2021	43	68.4%	38	54,855	Brakes — 44.7%
2023	45	80.5%	41	60,437	Lamps, reflectors and electrical equipment — 17.1%
2024	46	73.1%	52	65,460	Lamps, reflectors and electrical equipment — 30.8%

Common MOT Failures

Top failure categories across all test years for 1978 Triumph Stag, with age trends.

Lamps, reflectors and electrical equipment

27.1%

↓ Decreases with age

Suspension

26.9%

↓ Decreases with age

Lamps, Reflectors and Electrical Equipment

25.2%

↓ Decreases with age

Brakes

23.3%

↑ Increases with age

Noise, emissions and leaks

20.5%

↑ Increases with age

How Failures Change With Age

Comparing failure rates between the youngest and oldest test years.

Category	At Youngest	At Oldest	Change	Trend
Brakes	15.8% (31 yrs)	21.2% (46 yrs)	+5.4%	🔴 ↑

Other Manufacture Years

1970 1971 1972 1973 1974 1975 1976 1977 1978

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About This Data

This page shows how Triumph Stag cars manufactured in 1978 perform at MOT as they age. Data spans from 2009 to 2024, covering 1,546 tests. Pass rates naturally decline with age as components wear.

Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.