Pretty sure it is the same engine as I had in my old trusty CX of years gone by.

2.5 L turbo, old technology indirect injection but ultra reliable & surprisingly economical.

You need specific oil for Diesel engines as they are so dirty.

Diesel oil is high detergent to keep all the carbon particles that get past the rings in suspension in the oil.

So you will notice that within a few hundred miles of changing the oil it will be black again.

Find the cheapest 10 or 15w/40 Diesel oil suitable for Turbo charged engines, ASDA used to do 5L for about £9.

I used to change oil & filter every 3k miles.

i'd use 10w40 semi synthetic diesel oil, winter coming, will be a bit thinner to help with cold starting, I used this for all my taxi customers and changed it every 10k , the cars quite easily did 200k plus with no problem.

Something else I have just thought of, although its an old engine, if its a turbo it will have a cam belt, quite easy to change though, accessed from under the front o/s wing.

Sorry, don't agree, the oil doesn't 'wear out' it gets contaminated, especially with older engines which don't burn as cleanly, fortunatly they don't need expensive oil as long as the spec is matched and for that engine it means less than £10.00 per can.

I have run many of these engines to 200,000 - 300,000 miles, they wouldn't last that long on 15k oil changes.

The 1.9 is far better than the 2.5 this engine suffers from no end of head problems it was fitted to many Ivico vans and the xm whereas the 1.9 if properly treated will do a million miles without bother.