I am consistently having the same issue. I play via app on android btw.
I get to the last lap, like today lap 57/57 begins, i have easy enough fuel (over 3l today) and i fail to finish the race.
Can anyone explain? I guess I am misunderstanding something. From my point of view, it seems as if the last lap isnt actually the last lap.
I previously thought maybe the lap counter is based on the lead car. So it turns over the laps when #1 goes through, so maybe im misunderstanding how much of the race is left?