The main system to protect the engine and parts of your vehicle is the lubrication system.
motor vehicles use engine power to move passengers from a starting point to a destination. This can be carried out efficiently using the minimum fuel energy or not.
Driving a car with rusty wheel bearings, the handbrake stuck and the brake pads seized onto the discs. What would happen?
You would have to keep your foot on the accelerator, use loads of fuel and hope you got to your destination before the whole system tore itself apart. And where would all that excess fuel energy go? Heat The energy would be needed to overcome the friction caused by having solid surfaces in close contact.