Going to work everyday... Do you use your car or you go walking? - Contrast/Comparative paragraph

Everyday we have to go to many places and we should think about the time we spend on it, the effort and the consequences it has on the enviroment. Going by car is more expensive because you have to pay the gas and mantain the car. Also the car create many pollution and contaminate our air. However it is faster and comfortable but only if you have to go out from the city. On the other hand walking is free and we can safe some money because we don't need the gym anymore. Surely, it's better for our health and furthermore it's good for our mind because we can take a moment to think about us and not about anyother people. In addition, it's proved that walking to our job make us being more productive, relaxed and happy. To summarize, if you have the chance try to walk everyday and you will be happier.