I use AMSOIL with their synthetic fiber oil filters and when running their oil and filter, they will recommend 25K or one year oil change intervals. AMSOIL has had extended drain intervals recommendations when using their oils for 27 years now.
I have used AMSOIL for 12 years now in all my vehicles with no problems, Two years now in my D2. Their old filters would only go 12,500 miles so you had to change the filter 1/2 way thru the recommend interval, but not the oil. If you use any other filter you need to change the filter as recommend by vehicle manufacturer. I do not usually run it 25k. but close sometimes. If you run in more severe conditions, then you should change it sooner. You can send them an oil sample and they can tell you the condition of your oil in regard to still having the protection you need or needing to be changed. I run their 5W-40 European Formula that meets all the specs required with the AMSOIL EA-096 oil filter, as well as their Severe Gear Lube in my diffs & transfer case and their ATF in my tranny.
They have a syn motor flush that you run thru before you change over to AMSOIL to clean out the carbon build-up and I run that with a clean filter to get as much crude as possible in the filter from the flush. I usually run my first oil interval shorter thinking there may still be more crude cleaning out during that first run of syn. Everybody has their own comfort level, and for me I have worked my way up from the 3K mile change in years past to feeling comfortable with full 25K now.