What's the purpose of a catalytic converter?
- A To reduce fuel consumption
- B To reduce exhaust noise
- C To reduce toxic exhaust gases
- D To reduce engine wear
Why this is the answer
Catalytic converters are designed to reduce toxic exhaust emissions by up to 90%. They have a high normal working temperature and for this reason are inefficient when the engine is cold.
Why the other answers don't fit
- A
- To reduce fuel consumption — Fuel use is barely changed by it.
- B
- To reduce exhaust noise — Noise is dealt with by the silencer.
- D
- To reduce engine wear — Engine wear is a matter of oil and maintenance.
Where this comes from
- Driving: the essential skills — section 17
Rule numbers link to The Highway Code on gov.uk.
Where this question comes from
The question, its options and the explanation are reproduced word for word from the DVSA revision question bank under licence. The licence requires them to appear unaltered, so we cannot reword them and neither can anyone else — that is why you will meet the same wording on other sites. Everything else on this page is written by Theory Hub: the explanation of why each wrong answer is wrong, the topic guide and the revision notes.
Asked in: Driving Instructor (ADI Part 1)
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