To compare these two types of engines you have to know how a petrol engine works and how a diesel engine works. Petrol is more common so we can start there. In a modern petrol engine, the fuel is delivered to each cylinder of the engine by a fuel injector. The injector sprays a fine mist of fuel into each cylinder just above the intake valve. This mixes with air that comes in through the air filter and related air intakes, then flows through the intake valve of each cylinder.
Diesel fuel, on the other hand, works on a slightly different version of the same principle. A diesel is an internal combustion engine just like a petrol engine, but the fuel is delivered in a different manner. In a diesel engine, the fuel is injected directly into the cylinder and mixes with the air there. Since a diesel injector is located within the combustion area of the engine, it’s got to be much tougher than the petrol version. The magic of a diesel happens in the cylinders. Where a petrol engine needs a spark plug to ignite the fuel and air mixture, a diesel is able to ignite it simply by placing it under great pressure, which creates heat and causes the explosion. As a diesel engine warms up, so does its efficiency rise. It’s an amazing system, and wastes far less energy than the equivalent petrol engine. This is why the fuel consumption figures/ratings are so much better for diesel engines. So, diesel power cars from Mercedes, BMW and now Mazda return better kilometers per liter than their petrol powered siblings and they also deliver much more torque.
Test drive a diesel car today and FEEL for yourself the power delivery and the real time fuel cost per mile as you drive.
