Hi Don.
Most jag dealers use shell helix ultra C1 WSS-M2C 934-B so i am told , as Castrol used to be the Oil that was used but some use Mobil Oil which is not a C1 Oil. I haven't any experience with the s type but if it has a DPFilter i would use a C1 Oil and always use a Genuine Jaguar Oil Filter and sometimes drive it as if you had stolen the s type, as with a DPFilter the Engine as with all newish diesels has to be worked, don't always keep the Revs below 2.000.
Regards Tom.