Which one needs more maintenance, diesel engine or petrol engine? and why?

Petrol engines.
More servicing is required than a diesel (from experience).
Petrol engines require tune-ups, plugs replaced every year and the overall life expectancy of a diesel is far greater than a petrol, possibly by a100,000 if properly maintained.

diesel engine need more maintenance why ?i think , the small piece of diesel engine it work in hight tempereture so withoutmaaintenance the engine get a short life

diesel engine need more maintenance than petrol engine why ? because diesel engine require high pressure for firing because there is no spark_plug and this produce heat in all engine and heat makes the life time of engine become very short due to nuts loose or vibration which comes from the pressure or frction which takes place because of vibration

Diesel Engines needs more of Maintenance than Petrol

esel engine need more maintenance than petrol engine why ? because diesel engine require high pressure for firing because there is no spark_plug and this produce heat in all engine and heat makes the life time of engine become very short due to nuts loose or vibration which comes from the pressure or frction which takes place because of vibration.
and most diesel engines use lift pumps for fuel circulation and diesel is heavy while most petrol engines are direct injection and petrol is light.
The heavyness of diesel results mostly in the excessive use of oil while petrol excess use of oil is less.

Diesel engine and petrol engine both are significant on their places. Talking about maintenance issue, it entirely depends on following factors:•    How much approx distance per year the vehicle will travel.•    Depreciation rate.•    Fuel quality.•    Vehicle’s fuel economy.   Although, some people think that diesel engines are very noisy and requires more maintenance but it is not true in current scenario. Modern technology has overcome this problem and now diesel engines don’t make so much of noise.

diesel engines

Diesel engines don't necessarily require more maintenance than gas engines do.
In road vehicles, diesel engines and petrol engines have comparable maintenance intervals.
Automotive engines aren't designed to last any longer than they need to since automakers know that most vehicles will be replaced after10-15 years of light driving anyways.
Heavy Duty diesel engines seen in tractor trailers, locomotives, ships, etc.
have much higher service intervals and engine lifespans.
For these kinds of applications, Diesel is the only way to go.
Diesel engines do have a few maintenance issues that petrol engines don't:
1- If the diesel ever contaminates the engine oil it will not evaporate away like petrol will.
The diesel ends up diluting the oil leading to poor lubrication and engine wear.
Faulty fuel injectors may spray diesel directly on to the cylinder wall which ends up leaking across the piston and in to the crankcase.
2- Diesel fuel requires better filtering and removal of water to prevent issues with the fuel delivery system which must pump diesel at very high pressure through tiny jet nozzles without getting clogged,
3- Newer diesel engines have elaborate exhaust after treatment systems that require maintenance.
Some engines require refills of Urea for SCR systems and others require maintenance to regenerate the DPF (Diesel Particulate Filters) to clear them of soot.

the diesel engine will lead a big place in the world (the dependence on it more )& its component is more complicated than petrol engine EX: Heavy Duty Equipments is more spread , i knew europ Change the direction to produce Diesel Engine because it avilable & cheap

A diesel engine needs more maitenance than a petrol engine.
This is because most diesel engines use lift pumps for fuel circulation and diesel is heavy while most petrol engines are direct injection and petrol is light.
The heavyness of diesel results mostly in the excessive use of oil while petrol excess use of oil is less.