Diesel engine has more life than a petrol engine because of its robust design, lower rpm and lubricative nature of diesel, etc. Furthermore, the diesel engine has a higher oil capacity than the petrol engine, which benefits in the proper lubrication of engine components and extends engine life.
Which engine has more life petrol or diesel?
The diesel engines have more life in comparison with petrol or gasoline engines.
The longer life of a diesel engine is due to its superiority in a variety of factors like its design, operating speed, fuel characteristics, cooling system, lubrication, and so on. While the petrol engine has less life because of its higher RPM, lower lubrication, etc.
Why diesel engines last longer than petrol engines?
Following are some reasons that increase the life expectancy of a diesel engine than petrol engine:-
1] The design of diesel engines is more robust:-
The diesel engine works at a higher compression ratio (14:1 to 25:1) than the petrol engine (3:1 to 12:1).
Therefore the components of diesel engines are designed more rigid to sustain high pressure. Thus the diesel engine uses larger size bearings, crank, camshaft, etc which makes the diesel engine more robust than the petrol engine.
The diesel engine uses gears instead of a belt or chain, thus it lowers the possibility of failures of the different components like the oil pump, coolant pump, timing mechanism, etc.
Thus due to the robust design, the diesel engines take more time for considerable wear of their components.
2] Less corrosive combustion products:-
The diesel engine uses a higher compression ratio for the auto-ignition of the fuel and the petrol engine takes the help of a spark plug for the combustion of charge.
Thus the diesel engine gives better combustion of the fuel and produces less corrosive exhaust gases while the petrol engine creates corrosive exhaust gases that increase the chances of wear.
3] Lubricating nature of diesel:-
The diesel is a light oil and it has decent lubricating properties. Hence the use of diesel reduces the friction between moving components inside the engine and lowers the rate of engine wear.
Fuel used in petrol engines has corrosive nature that initiates the wearing of the engine surfaces earlier.
3] Higher oil capacity:-
The diesel engine has a much larger oil capacity than the petrol engine. The use of more oil improves the lubrication of the diesel engine components. The better lubrication lowers the wear of the engine components and helps to increase the life of the engine.
4] Diesel engine works at lower RPM:-
The diesel engine runs with higher torque and lower RPM while the petrol engine works with lower torque and higher RPM.
Thus the diesel engine provides the same amount of power within fewer revolutions of the crankshaft than the petrol engine. Thus to develop the same amount of power, the petrol engine has to perform more revolutions.
Hence due to the lower RPM, the wear in the diesel engine is slower than the petrol engines.
5] Lower exhaust temperature:-
The combustion in a diesel engine takes place at a higher temperature than in a petrol engine.
But because of the higher expansion ratio of diesel engines, the maximum energy of combustion products is converted into the work of expansion and thus the exhaust gases become cooler than in the case of the petrol engine.
The lower temperature of exhaust in a diesel engine lowers the rate of wear than a petrol engine.
Hence diesel engines have more life than petrol engines.