Why diesel engines are low speed engines when compared to petrol engines ?

Question

Why diesel engines are low speed engines when compared to petrol engines ?

Answer 1

Diesel engines have to be robustly built to withstand the very high compression in the combustion chambers. For robust read heavy, this as well as the limitations of the injection system restrict the feasibility of building a very high speed unit.

However diesel technology has come a long way in recent years, particularly in Europe, engines that will reach 6000 rpm are not uncommon nowadays.

Answer 2

Diesel combustion is slower.

Same way kerosine combustion is much faster, so it's used in very fast engines. And same with "jet fuel".

Answer 3

They have high revving diesels its not because its combustion is slower because higher octane gas in high power sports cars and race cars burns slower but makes more power it just can spin as high because it makes mostly torque due to the high compression required to make it explode instead of using a spark plug.

Your 20compression ratio diesel cylender chamber is already working twice as hard at 3000rpm then the gasoline engine with a 10 compression ratio at 6000rpm.