Petrol Engine Vs Diesel Engine

    Some time people confuse when they are buying a car. They don't know which to prefer, the car having petrol engine or diesel engine.There is huge difference in the prices of both the cars.The car having petrol engine is economically sounds than its counterpart.This difference is due to many structural variation between them.Here, I am providing you some information regarding internal combustion engines which will help you to understand  the function of I.C. engines and also you will be able to know what are the basic difference in petrol engine and diesel engine.

you should know -

what is an internal combustion engine?

In internal combustion engine combustion of fuel takes place with in the engine itself unlike a external

Car Engine- A Internal Combustion Engine

combustion engines.Steam turbines are the example of external combustion engine where steam is introduced to turbine after been produced in a external unit i.e. Boiler.

Now a days internal combustion engines are using widely because they are much more compact in size for a given out put.

How internal combustion engine works?
I.C. engines contains  cylinders with pistons and piston is connected to crankshaft with the help of connecting rod. (some big engines may have different arrangement) Combustion of fuel takes place in the cylinder which leads to give a reciprocating motion to the piston.Piston is connected to the crankshaft with the help of connecting rod.The function crank shaft is to convert reciprocating motion into rotatory motion.In the same way a fly-wheel is is fitted with the crank shaft. 

fly-wheel

We need a fly-wheel because it smoothen the cyclic fluctuations.In four stroke engines we get out put power only in power/expansion stroke so speed may fall during other cycle or  due to variation in load.To over come from this problem wee need to introduce a fly-wheel which connected to crank shaft.Basically it stores energy and releases it during any disturbance occurs. Thus it reduces cyclic fluctuation.

Rotatory motion of crank shaft is the used to propel the propellers and and to rotate alternators to generate electricity.

What do you mean by four stroke engines?

In four stroke engines piston has to make four strokes, two in upward and two in downward direction to complete the cycle.Name of these strokes are-

(1)Inlet or suction stroke

(2)compression stroke

(3)power or expansion stroke

(4)exhaust stroke

Four stroke engines have inlet and outlet valves unlike two stroke engines which are operated mechanically. The opening and closing of valves is controlled by cams which are fixed to the camshaft with the help of gear or chain drive from crank shaft.

PETROL ENGINES AND DIESEL ENGINES:   

4-stroke:six cylinder diesel engine

Petrol engines are spark engines i.e. combustion of fuel takes place with a spark.We need a spark plug in petrol engines to produce electric spark for combustion.
              In diesel engine we don't need any spark plug arrangement for the combustion.In diesel engine air is compressed up to ignition temperature of diesel oil and then diesel oil is sprayed in to the cylinder to perform power stroke.

It's amazing but true to know that  the diesel engines have greater efficiency than than the petrol engines because of high compression ratio in diesel engines.

                           

 DIFFERENCE BETWEEN PETROL ENGINES AND DIESEL ENGINES:

   PETROL ENGINES               

• Petrol engines have lower  efficiency
  

  

  Petrol Engine

• It require spark plug for ignition
  
• very low air-fuel compression ratio
• It requires less maintenance
• Very low pressure in compression stroke
  
• Less vibration can be  found
• It gives comparatively less mileage
• petrol engines have less cost
  
• Petrol engines have less  lasting tendency
  
• comparatively  lighter engines
• Petrol engines have  less  torque
  
• Petrol engines have very good pick up**
  

    DIESEL ENGINES

• Diesel engines are more efficient

  

  Diesel Engine

• Air is compressed up to ignition temp.  
• very high compression ratio
• It requires frequent maintenance
• comparatively high pressure
• vibration is more in diesel  engines
• Diesel engine gives more mileage than petrol engine
• Diesel engines are very costly
• Diesel engines are long lasting 
• Diesel engines are heavy       
• Diesel engines have higher torque**
• Comparatively pick up is not good 

** It can pull heavy loads easily than the petrol engines that's why diesel engine is used in heavy load carrier vehicles.
 **Petrol engines have very good pick up hence it is used in racer bikes and  racer cars like cars of formula -1.
These are some points which will surely help you to decide better while buying a petrol or diesel engine car.If you want to buy a car and want very less maintenance and also less noise then you should go with the car having petrol engine.
        But for a long period of running diesel engine car will economically sound because of it's mileage and comparatively cheaper rate of diesel oil as compare to it's counterpart.
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For any query regarding  this article please mail me:

            bhupeshmarine@gmail.com