Sorry for the naive question. Last year I bought a 2014 Fiat 500L second-handed, petrol. I noticed that the motor sounded a bit strange or "weak" (my friend says it sounds like a moped). I asked my garagist and he said "yeah it's normal, it's just that it runs on three legs." - "Eh?" - "Yeah, it's a three-time engine".
This was not in English so I'm not certain of the accurate translation. But it literally translated to "three time engine". I looked up "three stroke engne" but apparently it's a very specific kind of rotary engine that only exists on some Mazda cars. My garagist was in a hurry so I wasn't able to ask more specifics.
Looking at Wikipedia, I see that Fiat 500L has TwinAir Turbo, FIRE or Turbojet engne.