Back to the original question, my immediate reaction was thousands of XUDs because they were used in so many things - Citroens and Peugeots big and small, Fiat Scudo and Useless, etc. I had at least 4 over the years. But then I realised it must be almost 25 years since any were produced new, and as they are Euro 4 anyone regularly driivng into places like Bristol or Birmingham, and of course the London ULEZ, will have to spend £8 a day, £12.50 in London, so may have scrapped them. So perhaps not many at all.
One way to get a feel for it is to think about the 'big sellers', maybe the Peugeot 405 and 309 and others, and look them up on howmany left (.co.uk). If you ignore the suggested models that pop up and just click on the headline (e.g. Peugeot 405 - search) you can quickly scroll down + next page and count them as you go. Looks like there are only about 130 diesel 405s still registered, maybe 80 309s, but of you do that for more cars that used the XUD you might get a decent number. Only about 60 Citroen BX diesels, only 1 lonely Visa diesel. There may be more SORNed of course.
You need some 'model knowledge' - I looked up Fiat Scudo and found an encouraging 329 Scudo Ds registered, but clicking on that showed they were all post 2002 so likely HDi s.
I wonder how many went into motorhomes/camper vans? That might be a high value market as the body is worth far more than a car or van so owners might want to keep them alive as long as possible rather than scrap them.
Richard_C
Current:C4 Max Hybrid, C3 1.2 Auto
Past Citroens: Dyane (x2), 2CV, Visa, BX (x2), Xantia, Xsara Picasso, C4 Picasso,C3 (x2) C5 X7 Tourer, Synergie 1.9TD, C1
Others: Hillman Hunter, Cortina Mk1, Maxi, VWT2, Granada, SAAB 900, SAAB 9-5, R5 Gordini
MattBLancs wrote: 01 Jan 2026, 10:24
XUD turbo models had the oil filter housing mounted oil-water heat exchanger, not sure if non-turbo XUD did without? (Think the 206 DW8 didn't have one, from memory...)
Just to answer myself on this point:
The "My Engine" (XUD marinising) thread confirms, non turbo XUD, or at least XUD7, has no oil heat exchanger/ "cooler" but one can be fitted.
No cooler on images on page 1. One added later in the thread.
Sorry for dragging it away from the original question immediately after Richard_C's attempt to get it back in line!