The MOT Files

Exhaust and emissions

How long do exhaust system last?

Data updated

Quick answer

Across every car tested in Britain, exhaust system fail the MOT at 0.0 per 100 tests at three to five years old and 2.5 at 15 years and older — 104 times the rate. Failures reach half their peak from 12 to 14 years, which is when to have them checked. Silencers and pipes rust through from the inside on short-trip cars; rubber hangers perish.

Per 100 MOT tests

Exhaust system: failures and advisories by car age

FailuresAdvisories
3–5 yrsreg. 2020–2022
0.0
0.1
6–8 yrsreg. 2017–2019
0.2
0.9
9–11 yrsreg. 2014–2016
0.8
2.1
12–14 yrsreg. 2011–2013
1.6
4.2
15+ yrsreg. 2010 and earlier
2.5
7.0

Items recorded per 100 class 4 tests at each age, across the whole fleet. Advisories run ahead of failures: the tester saw the part wearing and said so a year or two before it failed. Peak band highlighted.

DVSA recorded wording

What the tester writes

When it fails

The defects behind it, explained

Common questions

How long do exhaust system last?
Across the British fleet, exhaust system barely fail before 12 to 14 years: 0.0 failures per 100 tests at three to five years, rising to 2.5 at 15 years and older, 104 times the rate. Silencers and pipes rust through from the inside on short-trip cars; rubber hangers perish.
At what age should I have exhaust system checked?
From about 12 to 14 years, when failures reach half their peak rate across the fleet. Advisories for exhaust system run ahead of failures by a year or two, so a car whose MOT history shows one is on the curve.
Is a worn exhaust system an MOT failure?
It depends on how worn. "Exhaust leaking or insecure" and "Exhaust mounting deteriorated or missing" are the defects testers record; each page explains the threshold at which the item fails rather than being advised.

Analysis built from DVSA data of