Furthest I have ever gone was 3 back to back oil changes on a wire backed Fram Ultra. No issues really, the oil was clean when I drained it after the last interval, so I assume it wasn't in bypass circulating dirt. I guess roughly 22,500 miles or so. The last interval was cut short a little bit because the weather was changing and I wasn't about to be changing oil in the snow. So the last interval was probably around 6,900-7,100 or so. So in total about 22,000 miles.