First off this is not a first aid question so you posted in the wrong section
Second you have not been very clear or specific with your question. For example are you asking what damage it does to the car by accelerating the car too fast? or are you asking how and why it uses more gas? The same goes for the break question.
Also you need to be more specific in your questions if you want in depth answers, like you asked how to keep your car in top shape? well a general answer would be drive to the guidelines set by the manufacture, get regular mechanical service check ups etc. But if you wanted a more in depth answers then you need to put details like what model and year the car is, how log you've owned it etc.