We are interested in an economical second car. Go up (or Mii/Citygo). Around the corner there is a CNG tank (m.W. gives the gas provider a subsidy to a new car). Approximately 15tkm/year mixed operation. Use your advice, which will probably come in the course of time more favorable, if you take into account the maintenance costs etc. (for gas certainly higher?) Another unknown with gas is the price development from 2018. And how is the durability of the gas drive compared to the 60P S engine?