How do turbo diesel engines produce high power with low CO2 emissions?
John P asked:
Given two similar engines, one petrol and one turbo diesel, how and why does the diesel develop similar power but with much lower CO2 g/km emissions? Does the diesel have any disadvantages over the petrol engine?
Caffeinated Content
Given two similar engines, one petrol and one turbo diesel, how and why does the diesel develop similar power but with much lower CO2 g/km emissions? Does the diesel have any disadvantages over the petrol engine?
Caffeinated Content
higher compression ratio = higher efficiency
The compressed air in diesel cars is so hot that when the fuel is injected, it readily burns so there is no need for spark plugs in diesel cars. Because of this, diesels can be accurately called “compression ignition engines” while petrol cars have “spark ignition engines.” There are no breakers or coils in the diesel like in petrol. Diesels do not have throttle plates. Power depends on the controlled, injected fuel. Electronic engine management is not necessary in diesels but some modern models already have electronically controlled pumps.
Advantages of the diesel engine over its petrol counterpart; In terms of performance, the latest versions of performance turbo diesel engines are controlled electronically. This way the torque produced is at par or simply better than that of petrol-driven vehicles. Diesels are not immune to cold and damp weather conditions. In theory, turbo diesels are more efficient than petrol cars. Cars running on diesel are much more environment-friendly. Diesels can reach more mileage than their petrol counterparts; Turbo charging a diesel car is much easier. Diesels are great for short trips because their ignition is not affected by temperature. Engines’ efficiency is high whether from a cold start or not. Diesel engines are built to last longer. The cold starts are the petrol car’s primary killer. Lubrication is damaged easily in petrol cars.
The disadvantages of diesel over petrol engines; Compression ratio of 22:1 is good for engine brakes but this makes it harder to start the engine. Owner should invest in a good battery and starter motor. Diesels would need glow plugs or electric heaters so that engine will start easily. One plug is needed per cylinder and each plug eats up 15 amps - which consumes battery. Diesel cars only gain about 70bhp with 1.9 liters of fuel versus the 100bhp in petrol cars. Diesel engines are heavy. Steering is heavy so you’ll need power steering option. Some modern turbo diesels run quietly but most are really noisy.
The emissions from a diesel can hardly be called low CO2 since the fuel being burned is a hydrocarbon and emits a very large amount of CO2.