I don't know about the 8 speed, but I wasn't happy with the way my 6 speed shifted when it had the same mileage, so I removed the negative battery cable for about 30 min. This reset the transmission computer and it settled down after that. It did take about 2000 miles to completely smooth out and now (at 6000 miles) is just as smooth as the 6 speed in my old 2010.