Castrol Edge Professional

[lim]

Originally Posted By: mjbi
The only recommended oil for this car is the Castrol Edge Professional 0w-20. I can find various versions of the Edge, but not the Edge Professional. Where can I find a retailer that sell this specification. If not, is there an alternative oil acceptable?


There is a difference between 'recommendations' on one hand and 'specifications and approvals' on the other.
This is what JLR say about the oil specification for V6 and V8 petrol engines:

"SAE 5W-20 engine oil meeting specification WSS-M2C925. If unavailable or, where ambient temperatures fall to lower than -20° C, SAE 0W-20 engine oil meeting Jaguar Land Rover specification STJLR.51.5122 should be used."

Regards, lim

 

[weasley]

Originally Posted By: CrawfishTails
I don't see much, if any, difference between an oil meeting dexos1-A1/B1 vs. dexos1-A5/B5 according to using the Lubrizol tool: https://www.lubrizol.com/apps/relperftool/pc.html

That said, I still think any dexos1 A1/B1 oil already out there would cover this Jaguar spec, since dexos has a new low-temp pumpability test added to match up to the Jaguar requirement, and the combined dexos1 and ACEA A1/B1 cleanliness tests are extensive enough.


The JLR spec requires first that an oil meets ACEA A5/B5 except for the HTHS requirement. It then goes on to add additional fuel economy demands (higher than that required for ACEA) and a lower CCS requirement than SAE require for 0W-20.

So it has to meet A5/B5 performance without the benefit of A5/B5 viscosity. dexos1 does not fully cover this (and, additionally, has a lower ash and lower TBN limit).

 

[Segillum]

Originally Posted By: weasley
The JLR spec requires first that an oil meets ACEA A5/B5 except for the HTHS requirement. It then goes on to add additional fuel economy demands (higher than that required for ACEA) and a lower CCS requirement than SAE require for 0W-20. So it has to meet A5/B5 performance without the benefit of A5/B5 viscosity. dexos1 does not fully cover this (and, additionally, has a lower ash and lower TBN limit).


It isn't explicitly clear that Edge Professional 0W-20 does meet A5/B5. The PDS states only that "Castrol EDGE Professional E 0W-20 is suitable for use in automotive gasoline and diesel engines where the manufacturer recommends the ACEA A1/B1 specification."

Can any 0W-20 meet A5/B5?

 

[weasley]

Originally Posted By: Segillum
Can any 0W-20 meet A5/B5?



No. SAE 0W-20 has a minimum HTHS @ 150°C of 2.6 cP. ACEA A5/B5 has a minimum of 2.9 cP. Theoretically you could make a 0W-20 with a higher HTHS, but there's little point in that given that 0W-20s are chasing fuel economy. This is why these new-style 0W-20 oils for EU applications often claimed A1/B1 (which allows 2.6 cP minimum for 0W-20), which is somewhat at odds with the modernity of their OEM approvals.

This is also where ACEA C5 came from - to make space for a modern, low-HTHS, mid-SAPS style oil, which many of the OEMs are specifying these days.

 

[Segillum]

Originally Posted By: weasley

SAE 0W-20 has a minimum HTHS @ 150°C of 2.6 cP. ACEA A5/B5 has a minimum of 2.9 cP. Theoretically you could make a 0W-20 with a higher HTHS, but there's little point in that given that 0W-20s are chasing fuel economy. This is why these new-style 0W-20 oils for EU applications often claimed A1/B1 (which allows 2.6 cP minimum for 0W-20), which is somewhat at odds with the modernity of their OEM approvals.


That's very interesting -- many thanks.

Makes me wonder whether a 5W-20 to the original WSS-M2C925A spec would be slightly better than an 0W-20 to the later JLR 51.5122 for a Jaguar XK.

 

[supercity]

Edge Professional A1 5w-20 (WSS-M2C925B now JLR.03.5004) also meets A5/B5 except for the HTHS and it existed before JLR specs were introduced. Edge Professional E 0w-20 (JLR 51.5122) is more an evolution than revolution. Strangely it's not totally backwards compatible according to JLR.

 

[supercity]

Originally Posted By: CrawfishTails


While manufacturer specs are nothing new, those German car maker approvals you mentioned mean you can choose from at least 3 or more easy-to-find COMPETITIVE sources in the FREE market. For JLR to threaten their customers with warranty denial when only 1 source is available is abusive to their customers. You can't tell me there is something so magically unique about those Jag engines that they need their own ONE oil. JLR could have their own spec, but could also allow the use of very-high-quality synthetic oils too for the person who doesn't want to donate $180 to the dealership for an oil change.


Mobil have an approved oil - Mobil 1 ESP 0w-20. Not sure why this or the approved Castrol oil is not available in the US, it is here.