Children test the boundaries of our patience and general knowledge as they ask many questions to expand their understanding of the world. Transportation and vehicles is a great mystery for the younger set, but you do not need to be a mechanic to explain the basic principles of how cars work. When explaining automobiles to a 5-year old, keep the explanation general and relative to concepts he already understands.
Explain that cars use gasoline as fuel. Go to the petrol station together and show him where the gas is pumped into the car. Present gasoline as an energy source, explaining that gasoline is like food for the car.
Open the bonnet of your car and point out the basic features, such as the battery and engine.
Show the child how the key goes into the ignition. Start the car and explain that turning the key in the ignition is like an "on" switch for the car. Look under the bonnet with the engine running to show the parts in motion.
Provide a basic explanation of combustion. Tell the child that when the car is turned on, the engine sucks in air and a small amount of gasoline, which causes a series of tiny explosions that provide power to the other parts under the hood that make the car move forward.
Show the child the steering wheel, throttle and brake. Explain that the steering wheel provides control for moving the vehicle, the throttle pedal is pressed to add more air and fuel to the engine to make the parts move faster, in turn making the car move faster and the brake pedal stops the vehicle when pressed.
Although computers, belts, filters and injectors are all vital to the workings of a vehicle, a simple, yet factual, explanation is best to satisfy a child's needs without overwhelming him. While explaining details of hw to start and control a car, stress that only adults can drive. An especially curious child may benefit from a trip to a mechanic's shop, where he can view different cars as they are repaired.
Do not touch any of the mechanics under the hood when the car is running. Not only are moving parts dangerous, but most of these parts get very hot.