408Stang, the
current JLR specification for the 0W-20 oil is STJLR.03.5006. It superseded the previous spec back in 2018. That may be why you are unable to find it. I bought the newest spec oil at the dealership parts department back in November. The part # is 15DA2C and it was $12.95 a quart although with today's petroleum prices it is undoubtedly higher. I checked with Castrol and they told me that oil was only available through dealerships and not sold through any online suppliers like Amazon, etc. (unless they happen to be a Jaguar dealer anyway).
Maybe check again and ask for the newest oil ?
I have a 2021 Jaguar F Type R with the supercharged V8. I too agree that the manufacturer recommendation of 15,000 mile OCI's is ridiculous. I changed out the factory fill on my car at around 2750 miles. You can read the Blackstone report here:
I dumped the factory fill oil and changed the filter at 2754 miles on my 2021 Jaguar F Type R and sent the sample to Blackstone Labs. The engine is the 5.0 Liter Supercharged V8. Note that Jaguar/Land Rover requires the specially formulated Castrol Edge Professional EC5, specification...
bobistheoilguy.com
One thing of note is the higher than expected titanium content and lower than expected moly content. Otherwise I'll bet the special Castrol Edge Professional EC5 oil that is sold exclusively at Jaguar dealerships is the same oil as their Edge Professional oil but with different moly and titanium percentages.
So JLR's engineers feel that high titanium content is beneficial to their engines. How do the other oils recommended in this thread compare with that ingredient ?
As part of the warranty, Jaguar does free oil and filter changes yearly for the first 5 years. Which for me means about a 5000 mile interval. They use bulk oil.
Here is a link to the Castrol Edge Professional EC5 0W-20 Data Sheet: