Flight Leonardo da Vinci–Fiumicino Airport departs from Rome Leonardo da Vinci–Fiumicino Airport at 10:45 and arrives at Istanbul Istanbul Atatürk Airport at 14:35.
The flighttime is about 2h 50m. The distance travelled ("as the bird flies"): 1844 Km. So the average speed is roughly 651 Km.
There is an 1 hour time difference between Rome and Istanbul