Does a diesel engines need a catalytic converters? The answer is no. A catalytic converter cannot be used on a diesel engine because it uses compression ignition instead of spark plugs to ignite fuel in the cylinder. So why do cars have them then?

If a diesel engine don’t have a spark that means the diesel engine doesn’t need a catalytic converter.

In a diesel engine, combustion happens without spark. The diesel engine is a compression ignition engine which means it uses fuel for ignition of the cylinder. In other words, diesel engines don’t burn fuel using spark plugs like gasoline engines do. Because of this, catalytic converters are not needed in a diesel engine because they don’t produce any harmful emissions or pollution.

Catalytic converters are usually used on vehicles that run on gasoline to reduce harmful gases produced during combustion by converting them into less harmful gases like carbon dioxide and water vapor through chemical reactions during the catalytic process inside these devices that can be found in your car’s exhaust system.

Diesel engines don’t use fuel for spark, instead, diesel engine is a compression ignition engine.

The diesel engine is an internal combustion engine that uses the heat generated by compression of air and fuel to ignite. Fuel is not used for spark. Instead, diesel engines use compression ignition, in which the fuel ignites from the pressure build up during combustion and not from a spark plug.

Because of this, they are able to operate at higher temperatures and pressures than gasoline-powered vehicles without risking knock (which can cause catastrophic engine failure). This means they can run leaner mixtures (more air than fuel), making them more efficient than their four-stroke counterparts. In fact, diesel engines produce about 40 percent more torque than their gasoline counterparts while using less energy per unit distance traveled! The result: better range and lower operating costs compared to gas-powered vehicles with similar power output levels

Catalytic converters can be used on a diesel engine to reduce harmful emissions from the exhaust, but it will reduce the fuel efficiency and increase your costs significantly.

Diesel cars do not need catalytic converters to help with emissions because they have a different system in place.

Diesel cars are more efficient than gasoline cars because they do not use fuel for spark. Instead, diesel engines are compression ignition engines. This means that the air and fuel is compressed before being ignited in the cylinder by a spark plug or glow plug. The higher temperature of this combustion process produces greater efficiency than what would be possible in an engine using spark-ignition alone.

Read More: https://autoremedy365.com/do-diesel-engines-have-catalytic-converters/

Diesel engines also produce hazardous emission. What ratio compared to Gasoline engines, I'm not sure.