They add different things to the car so that they can make the cars faster so they can go onto the market they also make the car more expensive so they can make more money. Don't know if that helps but there.
Answer:
The Oil.
The Tire Pressure.
The Brakes. ...
The Power Steering Fluid.
The Alignment.
The Antifreeze/Coolant.
The Tire Tread.
The Air Filter.
anything other than those main 8 shouldn't be something you need to keep an eye on
Explanation:
