Eli5: Why are petrol engines not built like diesel engines in terms of reliability?

Question

Diesel engines easily run 400.000km especially Mercedes cars but petrol will give up way sooner

In: Engineering

Answer 1

It’s a different principle. Diesel engines run at higher temperatures and pressures (making them more efficient). They don’t need spark plugs for example because they rely on auto ignition. This also removes the need for complex timing components.
So they have less parts.

In addition they also deliver more torque, which means you require less rpm for the same level of power (power = torque x rpm). This also means lower piston speed and less wear overall.