Question

A petrol engine has compression ratio from __________

(a) 6 to 10

(b) 10 to 15

(c) 15 to 25

(d) 25 to 40

I had been asked this question during an interview for a job.

My enquiry is from Comparison of Two Stroke S.I. and C.I. Engines in portion Two Stroke Engines of IC Engine

Answer 1

The correct answer is:

(a) 6 to 10

Petrol engines, which are spark-ignition (SI) engines, typically have a compression ratio ranging from 6 to 10. This is lower than compression ignition (CI) engines, as higher compression ratios in petrol engines can lead to knocking.