Triumph Stag: MOT pass rate and reliability data

The Triumph Stag passes its MOT first time more often than the average UK car, by 6.6 percentage points. These figures come from the DVSA's full year of anonymised MOT results, covering 960 individual Triumph Stag tests. Nothing here is an estimate or a survey.

The numbers

What this means if you are buying one

A 83.3% first-time pass rate means roughly 17 in every 100 Triumph Stags presented for MOT fail on the first attempt. That is better than average, so a well-kept example is a reasonably safe used buy. The average Triumph Stag tested had covered 51,476 miles and was built around 1975.

What this means at salvage auction

Pass rate is a proxy for what a car costs to keep on the road. The Triumph Stag sits 6.6 points above the national average, ranked 1,328 of 2,005 models. On one bought as repairable salvage, the mechanical side is less likely to spring surprises, so your repair estimate should hold up reasonably well.

Before you bid: run the lot through the analyzer, check the car's own record, check the mileage, decode the VIN, and if it carries a marker use the write-off value calculator. Or compare it against another model.

Looking at a specific Triumph Stag rather than the model in general? The free check covers its MOT and mileage history, and the full HPI report confirms the insurance write-off category, outstanding finance and whether it is recorded stolen, from licensed data for 5 credits. Already own one that has been damaged? Work out whether fixing it beats selling it with the repair or scrap calculator, and see recorded closing bids for damaged Triumph Stags at UK salvage auction.

Most common MOT failures on a Triumph Stag

1. Emissions levels exceed default limits, 2.2% of tests (6.2x the national rate for this defect)
2. Brakes imbalance across an axle such that the braking effort from any wheel is less than 70% of the maximum effort recorded from the other wheel on the same axle., 2.7% of tests (5.2x the national rate for this defect)
3. Vehicle structure corroded to the extent that the rigidity of the assembly is seriously reduced, 2% of tests (4.8x the national rate for this defect)
4. A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 2% of tests (3.03x the national rate for this defect)
5. Significant brake effort recorded with no brake applied indicating a binding brake, 2.2% of tests (2.11x the national rate for this defect)
6. Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc, 1.6% of tests (2.1x the national rate for this defect)
7. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 3.2% of tests (1.92x the national rate for this defect)
8. A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED, 2% of tests (1.62x the national rate for this defect)
9. Parking brake efficiency below minimum requirement, 1.6% of tests (1.2x the national rate for this defect)
10. A suspension pin, bush or joint excessively worn, 2.9% of tests

From 958 DVSA-tracked Triumph Stag tests, 2024. DVSA testers marked 2.5% of these flagged Triumph Stag defects as "dangerous", meaning the tester judged the car unsafe to drive away, against 5.11% nationally.

Most common MOT advisories on a Triumph Stag

An advisory doesn't fail the car - the tester flags it as worth watching, but it still passes. A different list from the failures above: what testers are noting on a Triumph Stag before it actually fails on it.

1. Excessive radial movement between the top of the steering column and the shaft indicating an excessively worn top bearing, 2.5% of tests (92.61x the national rate for this advisory)
2. A wheel bearing with excessive play, 12.6% of tests (19.46x the national rate for this advisory)
3. Power steering fluid leaking or system malfunctioning, 2.7% of tests (11.24x the national rate for this advisory)
4. Free play in the steering, measured at the rim of the steering wheel is excessive, 1.8% of tests (9.31x the national rate for this advisory)
5. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 19% of tests (3.42x the national rate for this advisory)
6. Excessive fluctuation in brake effort through each wheel revolution., 2.2% of tests (2.59x the national rate for this advisory)
7. The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired, 2.6% of tests (1.72x the national rate for this advisory)
8. Vehicle structure corroded to the extent that the rigidity of the assembly is seriously reduced, 2% of tests (1.59x the national rate for this advisory), also fails
9. Significant brake effort recorded with no brake applied indicating a binding brake, 2.4% of tests (1.2x the national rate for this advisory), also fails
10. A suspension pin, bush or joint excessively worn, 8.2% of tests, also fails

From 958 DVSA-tracked Triumph Stag tests, 2024.

Other Triumph models

• Triumph Tr6 - 87%

Models with a similar pass rate

• Ford Transit Custom - 83.3%
• BMW X5 Xdrive45e M Sport Auto - 83.3%
• BMW 4 Series - 83.3%
• Audi Q7 - 83.2%
• Ford Transit Custom 280leader Eblue - 83.2%
• Vauxhall Corsa E Se Nav - 83.2%

If this car is a salvage or write-off

• What does Cat N mean? Category N explained
• What does Cat S mean? Category S explained
• Cat S vs Cat N: the real differences
• Do you need an HPI check on a car you know is a write-off?

Embed this data

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All 2,005 models ranked by MOT pass rate