Question

What is the most probable scientific explanation behind the Euro 4 standards having “no limit” on the

particulate matter (PM) emitted by vehicles that run on petrol?

a) Petrol vehicles did not emit PM.

b) PM emitted by petrol vehicles was less harmful than diesel vehicles.

c) PM from petrol vehicles was not likely to have harmful effects.

d) Car manufactures had designed petrol engines that did not emit PM.​

Answer 1

Correct answer

b) PM from petrol vehicles was not likely to have harmful effects

Answer 2

b) PM emission by vehicles are less harmful that the diesel vehicels.

Explanation:

• PM emissions are due to carryover of non-combustible traces of constituents present in fuel.
• These emissions are negligible, they have natural gas firing.
• It has low ash content so a marginally significant natural gas firing is observed.
• Petrol vehicles emit less harmful PM than diesel vehicles.
• So, option b) is correct.