Well, here it is. I put it in on 12/4/2019 and drained it 9/3/2020. 22,000 miles, Averaged 2400 miles per month. I'd say 70 percent interstate driving. Used a Fram XG3600. Specs say use a 3614 but a 3600 fits and clears and gives me double the capacity. Interesting that the 10K rated XG Fram seemed to have done a great job at 22K. I had used the old formula Supertech 10W-30 Synthetic to 15K and Blackstone said try 17K. I used Rotella T5 15W-40 for about 15K next go round with good life left. Looks like I pushed the envelop for sure this time. I had intended to change at 20,000 miles but life got in the way. I'll be sticking to 15K-17.5K intervals from here on out. Got Carquest/Amalie HM Synthetic with a Fram Ultra Synthetic Filter(Advance Auto Parts Oil Change Deal). I thought this oil would have held up a bit better since it is ROTELLA HEAVY DUTY SYNTHETIC but then hey that's why I pushed it .........to see what the limits were. I think I found them! Yes, I know it was not SN rated. Back to properly rated oils now. Carry on.................................................