Group B Emissions, Smoke and Vehicle Conversions
Select the correct petrol emissions or diesel smoke procedure for kit cars, engine changes, conversions and cases where equipment or book data is unavailable.
How to prepare for this year's assessment
Start with group and vehicle class, confirm whether a rule applies, follow the prescribed inspection or administration method, and classify only the evidence permitted by the live source.
Core concepts
Concept 1
Select the correct petrol emissions or diesel smoke procedure for kit cars, engine changes, conversions and cases where equipment or book data is unavailable.
Exam cue: Identify whether the scenario belongs to Group A or Group B before selecting a manual.
Concept 2
Establish fuel, engine, vehicle dates and reliable data sources before selecting the test type and limits.
Exam cue: Establish fuel, engine, vehicle dates and reliable data sources before selecting the test type and limits.
Concept 3
Kit cars, different engines, conversions and missing equipment or emissions-book information are explicit 2026–27 subjects.
Exam cue: Use the source version and effective date that apply during the live 2026–27 training year.
Concept 4
Do not invent a limit or skip a test merely because an exact database match is unavailable.
Risk pitfalls and guardrails
Using registration date alone after an engine change or selecting default limits without following the manual hierarchy.
Guardrail: Do not replace current manual wording with workshop preference, memory from an earlier year or an assumption based on appearance.
Treating workshop repair preference as the statutory MOT test outcome.
Guardrail: Do not replace current manual wording with workshop preference, memory from an earlier year or an assumption based on appearance.
Reproducing a sample answer without checking current application and evidence.
Guardrail: Use public examples to identify concepts only; the live source and current facts control the result.
Memory anchors
Build the Date Evidence
Vehicle and engine evidence determine the applicable route.
Follow the Data Hierarchy
Use the manual sequence when exact equipment information is missing.
Test Route Before Limits
Choose basic, catalyst or smoke procedure before judging the result.
Group B Emissions, Smoke and Vehicle Conversions: Source
Confirm the answer in the live DVSA guide, inspection manual or applicable special notice.
Group B Emissions, Smoke and Vehicle Conversions: Sequence
Identify group and class, confirm application, use the prescribed method, then classify the evidence.
Group B Emissions, Smoke and Vehicle Conversions: Annual Boundary
Keep the 2026–27 assessed topic allocation separate from live rule changes and earlier training years.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
From which first-use date are spark-ignition vehicles normally subject to the emissions test, unless exempt?
A petrol car was first used in July 1975. What must be recognised before inserting a probe?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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