DS3 Diesel or Autogas?

Hello =) I am looking for a new car, which I will only need in a year, but I would like to inform myself now which car and which fuel variant, so that I can beat then, when a great offer comes. I will drive in one year during the week daily about 100km and at the weekend certainly also so 50km. What would you recommend me there? The DS3 Diesel e-HDi 110 (112Ps) or the gasoline DS3 THP 155 (156PS) which Which one is probably the most advantageous in the total maintenance costs? So fuel, insurance, TÜV, repair or maintenance costs? Can you easily upgrade the DS3 or are there often problems with it? I am still skeptical about car gas, but my uncle swears on it and with the rising fuel prices I start to tend to car gas. I would be very happy about many good tips. LG