1978 Triumph Stag Auto — MOT History by Age

How cars manufactured in 1978 perform at MOT as they age

48 years

Current Age

81.3%

Latest Pass Rate

1,114

Total Tests (All Years)

47,967 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 Auto as it ages.

31 yrs66.7%

→ ↑2.6%

32 yrs69.3%

→ ↓0.1%

33 yrs69.2%

→ ↓7.1%

34 yrs62.1%

→ ↑5.2%

35 yrs67.3%

→ ↑7.7%

36 yrs75.0%

→ ↓7.3%

37 yrs67.7%

→ ↓2.1%

38 yrs65.6%

→ ↑7.7%

39 yrs73.3%

→ ↓7.9%

40 yrs65.4%

→ ↑3.8%

41 yrs69.2%

→ ↓0.6%

43 yrs68.6%

→ ↑8.8%

45 yrs77.4%

→ ↑3.9%

46 yrs81.3%

📊 View as table

Age	Pass Rate	Tests
31 yrs	66.7%	105
32 yrs	69.3%	101
33 yrs	69.2%	107
34 yrs	62.1%	103
35 yrs	67.3%	101
36 yrs	75.0%	96
37 yrs	67.7%	99
38 yrs	65.6%	96
39 yrs	73.3%	101
40 yrs	65.4%	52
41 yrs	69.2%	39
43 yrs	68.6%	35
45 yrs	77.4%	31
46 yrs	81.3%	48

Pass Rate Trend

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

📊 View as table

Built	Pass Rate	Tests
2024 (46 yrs)	81.3%	48
2023 (45 yrs)	77.4%	31
2021 (43 yrs)	68.6%	35
2019 (41 yrs)	69.2%	39
2018 (40 yrs)	65.4%	52
2017 (39 yrs)	73.3%	101
2016 (38 yrs)	65.6%	96
2015 (37 yrs)	67.7%	99
2014 (36 yrs)	75%	96
2013 (35 yrs)	67.3%	101
2012 (34 yrs)	62.1%	103
2011 (33 yrs)	69.2%	107
2010 (32 yrs)	69.3%	101
2009 (31 yrs)	66.7%	105

Year-by-Year MOT Results

2009

66.7%

Age (yrs) 31Tests 105Avg Mileage 54,306Top Failure Lamps, Reflectors and Electrical Equipment — 18.1%

2010

69.3%

Age (yrs) 32Tests 101Avg Mileage 60,865Top Failure Lamps, Reflectors and Electrical Equipment — 15.8%

2011

69.2%

Age (yrs) 33Tests 107Avg Mileage 55,620Top Failure Lamps, Reflectors and Electrical Equipment — 15.9%

2012High Fail Rate

62.1%

Age (yrs) 34Tests 103Avg Mileage 57,569Top Failure Suspension — 21.4%

2013

67.3%

Age (yrs) 35Tests 101Avg Mileage 56,768Top Failure Suspension — 33.7%

2014

75.0%

Age (yrs) 36Tests 96Avg Mileage 53,985Top Failure Brakes — 32.3%

2015

67.7%

Age (yrs) 37Tests 99Avg Mileage 56,154Top Failure Suspension — 32.3%

2016

65.6%

Age (yrs) 38Tests 96Avg Mileage 56,685Top Failure Lamps, Reflectors and Electrical Equipment — 43.8%

2017

73.3%

Age (yrs) 39Tests 101Avg Mileage 57,547Top Failure Lamps, Reflectors and Electrical Equipment — 27.7%

2018

65.4%

Age (yrs) 40Tests 52Avg Mileage 49,556Top Failure Suspension — 30.8%

2019

69.2%

Age (yrs) 41Tests 39Avg Mileage 50,134Top Failure Suspension — 41.0%

2021

68.6%

Age (yrs) 43Tests 35Avg Mileage 47,420Top Failure Suspension — 60.0%

2023

77.4%

Age (yrs) 45Tests 31Avg Mileage 47,842Top Failure Noise, emissions and leaks — 22.6%

2024

81.3%

Age (yrs) 46Tests 48Avg Mileage 47,967Top Failure Lamps, reflectors and electrical equipment — 25.0%

MOT results for 1978 Triumph Stag Auto by test year
Test Year▲	Age (yrs)▲▼	Pass Rate▲▼	Tests▲▼	Avg Mileage▲▼	Top Failure▲▼
2009	31	66.7%	105	54,306	Lamps, Reflectors and Electrical Equipment — 18.1%
2010	32	69.3%	101	60,865	Lamps, Reflectors and Electrical Equipment — 15.8%
2011	33	69.2%	107	55,620	Lamps, Reflectors and Electrical Equipment — 15.9%
2012	34	62.1%	103	57,569	Suspension — 21.4%
2013	35	67.3%	101	56,768	Suspension — 33.7%
2014	36	75.0%	96	53,985	Brakes — 32.3%
2015	37	67.7%	99	56,154	Suspension — 32.3%
2016	38	65.6%	96	56,685	Lamps, Reflectors and Electrical Equipment — 43.8%
2017	39	73.3%	101	57,547	Lamps, Reflectors and Electrical Equipment — 27.7%
2018	40	65.4%	52	49,556	Suspension — 30.8%
2019	41	69.2%	39	50,134	Suspension — 41.0%
2021	43	68.6%	35	47,420	Suspension — 60.0%
2023	45	77.4%	31	47,842	Noise, emissions and leaks — 22.6%
2024	46	81.3%	48	47,967	Lamps, reflectors and electrical equipment — 25.0%

Common MOT Failures

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

Lamps, Reflectors and Electrical Equipment

24.4%

↑ Increases with age

Lamps, reflectors and electrical equipment

24.0%

— Consistent

Suspension

23.9%

— Consistent

Noise, emissions and leaks

21.5%

↑ Increases with age

Brakes

20.9%

— Consistent

How Failures Change With Age

Comparing failure rates between the youngest and oldest test years.

Category	At Youngest	At Oldest	Change	Trend
Suspension	12.4% (31 yrs)	10.4% (46 yrs)	-2.0%	🟢 ↓
Steering	10.5% (31 yrs)	12.5% (46 yrs)	+2.0%	🔴 ↑
Brakes	15.2% (31 yrs)	14.6% (46 yrs)	-0.6%	⚪ —

Other Manufacture Years

1971 1972 1973 1974 1975 1976 1977 1978

← Back to Triumph Stag Auto overview

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About This Data

This page shows how Triumph Stag Auto cars manufactured in 1978 perform at MOT as they age. Data spans from 2009 to 2024, covering 1,114 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.