Engine oil for 1996 Tdi (2.5l turbo deisel)

looking for an oil for the above.
Cost of the semi synthetic I was using has gone through the roof.
Kerax make a universal agricultural oil in 15w40, used in most heavy duty petrol and deisel farm machinery.
The spec for the 300 tdi says API-CD, this specification is now obsolete ( created in 1955).

I do not see any reason to fork out hard earned cash for fully synthetic, when originally the spec was mineral.

Anyone any suggestions for a suitable 'agricultural oil' available in the uk?
Thanks in advance
TH3

Any idea what the manual says ?

15w/40 will suffice

Loads of the stuff on eBay, the SAE grade is 40 so if you want something that is good for a lower ambient temperature the go for the 10w40 https://www.ebay.co.uk/itm/15w40-Di...154431?hash=item1cb85c813f:g:8UgAAOSwW4Zbj58G

But is it ok to exceed the API CD spec?

And the Kerax 15w/40 states heavy duty, but no reference to turbo!

Yes tractor oil could be less in price, but any part/semi synthetic or mineral oil the meet or supersedes LRs specification will do, and replaced when due.
This is spec for the engine oil for your engine when it was fitted into the disco 1. No doubt it’s the same in you4 owners handbook.

Comma's type XS semi synth 10w-40 is around £2.50 a litre if you buy it in the 20l tubs, still only around £2.80 in the 5l tubs as well, can be cheaper when on sale, far exceeds the ancient API CD spec

Stick your reg number in this site:
https://www.commaoil.com/products

I use this in my 1998 300Tdi....£25 for 10L
https://www.ebay.co.uk/itm/2-x-5-L-...res-10-W-40-/292834222937?hash=item442e47a359

Cheap enough that I don't scare myself at changing it every 3000 miles (about 10-12 months) and seems decent enough quality.