Originally Posted by MJsModelA
What is it about a diesel motor that gives is its distinct sound? As I was stuck in traffic here in WA state a diesel truck pulled along side of me and I wondered what makes it sound so different than a regular gas operated motor?
It is mainly due to the ignition being brought about by a case of severe detonation. The fuel/air is ignited not by a spark plug, but by such a high compression ratio that it causes a rise of temperature inside the combustion chamber high enough to light off the diesel fuel.