Why Do Diesel Engines Make More Torque Than Gasoline Engines?

August 27, 2018 @ 7:20 pm
Diesel engine

Why Do Diesel Engines Make More Torque Than Gasoline Engines? 

If you’re a car lover, you probably know that diesel engines are traditionally more powerful than regular gasoline engines. Of course, there are a number of components that go into a powerful engine, and a poor engine that runs on diesel isn’t always the fastest. Many people prefer diesel engines because they produce more torque and, in general, cost less in fuel expenses. 

But why does a diesel engine make more torque than a regular gasoline engine, and what benefit does this provide a driver?

How diesel engines work 

Unlike gasoline tanks that require a spark to ignite, diesel engines actually compress the air. This compression heats up the diesel fuel to such a degree that it leads to combustion, which propels the car or truck. Regular gasoline engines do not do this, as the fuel isn’t intended to combust via compression. 

In addition, diesel engines are two-stroke or four-stroke, meaning the pistons have two or four strokes to make before combustion occurs. Because of the compression, and the pressure and heat of the fuel, a vehicle is pushed forward at greater speeds than a regular gasoline engine. 

This internal combustion and compression is what leads to greater torque, as well.

What is torque? 

Torque is defined as a “twisting force that causes rotation,” and in the case of diesel engines, that rotation leads straight to the wheels. It’s also the rotation of the pistons in the engine that powers the wheels. It isn’t just a single rotation that gives a car power, however. Instead, it’s constant fuel injection that allows torque to continue, and to build on itself.

Why torque is increased in diesel engines 

In a diesel engine, stroke length (2 or 4) and cylinder pressure are the main factors that increase torque. Longer strokes give pistons more leverage as they rotate, which creates more force – or pressure – on the cylinders. Diesel engines are designed with longer strokes in mind, as this produces more torque and more power. The more pressure built in the strokes and cylinders, the more torque the wheels will have. 

The combustion temperature of diesel fuel is also designed for higher torque. Diesel engines use air compression, as mentioned above, to combust the fuel. With faster compression rates, the fuel combusts faster, allowing fuel injection to build on the level of torque. 

Last but not least, diesel engines tend to be designed for turbo charge. They’re heavier but able to handle the increased amount of energy the fuel produces. Their lean air-to-fuel ratio also helps diesel fuel go longer and add extra torque. Diesel fuel also has more energy per gallon than gasoline, which makes diesel fuel more efficient for combustion and torque. 

Why choose a higher torque engine? 

Overall, diesel engines definitely produce more torque, but that’s not always associated with horsepower. However, torque is responsible for the force of the wheels, which can make a car more reactive and faster. Many people who prefer speed and responsiveness when accelerating, turning, etc. prefer a high torque engine. Which do you prefer? High torque or high horsepower?