Franz Filter

I have a Frantz filter on my Pajero 2.8 ITD . Have extended the oil changes from 5000 to 30000k with regular oil analysis from William Adams in Melb. No doubt this could be extended further and I will probably do so. The oil adatives get replentished every 5000k with the Frantz filter change [1 litre oil + a toilet roll]. The particulate count is the same at 30000 as is at 5000. I have read where some opperaters have extended out to 100000k, but I would not recomend that without proper oil testing along the way. Hope this helps Stan