Hi there! Well, a fuel leak doesn't really affect your driving but it is dangerous to just leave it like that. If you noticed that you have to re-fueled more than usual, the leak is serious. Furthermore, gasoline is highly flammable thus it might cause a fire. Fuel leak too causes side effect which can lead you to gain dizziness when driving and that is not safe for you and other pedestrians! Therefore, you need to get your car fixed.