Why can a constructor signature be overridden? What is this convention for?

Question

PHP

The code below will work for the constructor.
For any other method, no, and it's reasonable for a child to implement the parent's method in a different way rather than doing the complete opposite

class Car
{
  protected $engine;
  protected $wheels;
  public function __construct(Engine $engine, Wheels $wheels)
  {
    $this->engine = $engine;
    $this->wheels = $wheels;
  }

  public function engineStart()
  {
    $this->engine->start();
  }
}
class Bmw extends Car
{
  public function __construct(Wheels $wheels) // ! damn, its OK !
  {
    $this->wheels = $wheels;
  }
}

(new Bmw)->engineStart(); // Trying to call method on null

Answer 1

The parent cannot know what might be needed to instantiate the child.
Not ok. There is no call to the parent's constructor in the constructor of the child

Answer 2

Well, in general, it is on the conscience of the developer, in this case, compliance with the Liskov substitution. Concerning the constructor, it is often redefined to add a parameter or additional initialization, but the parent constructor must be called with the correct parameters passed to it.