If you are an auto enthusiast you might have noticed that Diesel engines make more torque than petrol engines.

Let's start with WHAT IS TORQUE?

        Torque is simply the tendency of a force to turn or twist.
        A simple way to calculate the magnitude of the torque is to find the length and then multiply it by the applied force.


So here we are going to talk about a few reasons 

WHY DIESEL ENGINES MAKE MORE TORQUE THAN GASOLINE ENGINES? 



  • COMPRESSION RATIO

          If we look at the Petrol engine as the piston is moving towards the top dead center it will stop at some distance and move backward whereas in the Diesel engine the piston moves completely towards the top dead center to compress the air even further.

           So, Why does the Diesel engine compress the air more?
    This is because the Diesel engine does not have any spark plug, it has to rely on the heat of the air to instantly combust the fuel as it is injected. So it is raising the above air and self-ignition temperature of the fuel by compressing the air more.


             There is a direct correlation between the efficiency of an engine and the torque it produces so these higher compression ratios convert into more torque for Diesel engines.


  • SPEED OF COMBUSTION

             As we know, in a petrol engine a spark starts the ignition of that air-fuel mixture whereas in the Diesel engine the fuel instantly combusts as it is injected so complete combustion occurs much sooner when compared to the Petrol engine.



            If you look at the pistons as they are moving downward, the piston in the petrol engine moved down quickly compared to the piston in the Diesel engine before the complete combustion has occurred


            So the result is that the piston in the Diesel engine is spending more time with the air-fuel mixture when compared to the piston in the petrol engine which converts into more useful work and therefore more torque is produced.


  • BORE & STROKE LENGTH 

           Generally, Diesel engines have more stroke lengths and Petrol engines have less stroke lengths when compared. As discussed, torque is nothing but the product of force and distance.

          So in the Diesel engine, you will not only get much force but the distance is also more (the distance rotating around the crankshaft) so finally, the Torque is also more

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  • ENERGY DENSITY

         The energy density of Diesel is much higher than Petrol So if we consider a liter of Diesel and Petrol the energy in Diesel is higher than the energy in Petrol, Which results in more Torque.