I've been running my Peugeot 405 SRDT using a minimal modification single tank system for about a year now. To start with all I did was remove the thermostat connection for the (factory) fuel warmer and just drove it on SVO. It could be a but hard to start on cold days but once warmed up drove just fine. The fuel filters are quite cheap on this model (I usually buy them from micksgarage.com in Ireland and get them for around $8 a piece including shipping) so I never worried about a pre-filter and just kept a spare with me in the boot for quick changing.

At one point I bought half a dozen Bosch branded filters and noticed that instead of getting at least 4000km from a filter I was getting more like 400km. At first I thought this might be because it was in springtime so with the warmer temperature more animal fat was likely getting through my home filtering. But just to confirm I added a cheap lift pump and pre-filter, but found that the secondary filter (the Bosch one) continued getting blocked even as the pre-filter was fine.

I don't imagine this is important, but the pre-filter is a CAV filter, with a metal bowl so I can tighten it up hard enough that it doesn't leak. I picked up around 60 unbranded CAV filter cartridges for about $2 each so this is an economical option for me.

Continuing to explore options, I thought maybe it was something about the Bosch filter so I went and bought some Japanparts filters which were also cheap. And lo and behold more than 5000km later the first one I put in is still going fine. I still have the pre-filter in place and have not changed it either.

So I wonder has anyone else had comparable experiences? The filters all look more or less identical. Is it possible the Bosch one is filtering much finer (seems unlikely to me that this is the problem considering my home filtering includes 1 micron filter cloth), or is it just something about the manufacturing of them that makes them clog when using veg oil?