I had been looking into the reason behind my 626 diesel having two oil filters, one is a "bypass" filter.
What is the reason behind it ? here is a good explanation : By-Pass Oil Filtration
For me I need to consider shifting the arrangement as I want to fit a turbo to my engine, and it would sit where the current full flow filter sits. I may need to consider a relocation kit as getting the factory parts for an RF-T or RF-CX are going to be next to impossible.
the arrangement has changed over the years, the early GCs had the bypass filter on the chassis rail. Later they attached it to the block. and by 1987 the bypass oil filter had been ditched entirely to be replaced with a "combined" oil filter...maybe this had something to do with space.
Here is a pic of where my bypass oil filter sits :
Here is where its sits on an RF-CX, there is only 1 its a combined type :
And here is where it is on an R2 :
Once again must be a combined type filter as there is only 1.
I'll add some of the other cars oil filter positions soon.