I was lucky with 2 long trips this moring, however the second trip is 13km more than first one, the fare even less. What's wrong here, the answer I've got from uber is due to the Upfront Fare. O~~~, the first time I notice there is a so severe impact on the fare when consider the Upfront Fare. Next time when you get significant less than usual, don't bother to contact Uber, just keep going on. What a waste of the time,because the answer is so easy: Upfront Fare. And uber's reply says sometimes the Upfront Fare is high than usual, hope I can get the higher one in the future.