I don't know of any specific data but I have never read about or heard of any AJ133 or AJ126 engine damage caused by using correct spec oil but not the Castrol Unobtainium.
I have been using Aussie brands Penrite and Nulon full synthetic 5W20 meeting the spec Ford WSS M2C945-A for many years now in both my old XFR and current F-Type with zero engine problems in either car.
IMHO the JLR insistence on using the Castrol brew is simply a marketing ploy and a way for dealerships to extract some extra $ from the customer when doing an oil change.

 

Light weight oils are used to help meet mileage reqrirements. Higher mileage or better engine protection. Your choice.

 

One grade thicker won't hurt anything. @Martyb you could use either of the weights you mention.

Mobil1 Extended Performance meets the Ford specs as does Pennzoil Ultra Platinum.



Do our engines have variable valve timing? THAT can be a factor regards oil weight.

 

Yep, variable valve timing on both the inlet and exhaust valves on all AJ126 and AJ133 engines, JLR call it Variable Camshaft Timing (VCT).
Operated by solenoids rather than hydraulic.
The NA 5.0 also has two distinct intake camshaft profiles, again operated by solenoids. JLR surprisingly call it Camshaft Profile Switching (CPS).
It's all explained in the AJ133 Technical Training PDF, get it from my Dropbox here: https://www.dropbox.com/s/8y4iax9hm2...%20V8.pdf?dl=0

 

So, if it is controlled electrically (not by hydraulics) thicker oil shouldn't affect anything.

Some Chrysler engines are finicky about oil weight because they use hydraulic cam-timing systems.

 

Yeah....another discussion about oil....

 

 

 

Jaguar don't service cars within warranty any more with Castrol Edge, this side of the pond..

They have a deal on with Mobil. It's now JLR spec.

 

 

Jaguar list the recommended oil as 0W20 specification STJLR.51.5122

Initially Castrol Edge Professional E 0W20
Matched but I believe this has been discontinued in UK and replaced with

​Castrol Edge Professional E C5 0W20​​​​​​

There are several other oils that match
STJLR.51.5122

Fuchs Titan GT1 EVO 0w-20

Mobil 1 ESP x2 0W-20

Motul SPECIFIC 5122 0W-20

RAVENOL ECS, 0W-20,

May be others in your region
My advice look for 0W20 to spec STJLR.51.5122

 

if your car is under warranty then do as the manual says and you are safe. if warranty is over then do what you want, is's your car. Just don't complain if you have issues.

 

The manual and stickers/signs under the bonnet say Castrol Edge Pro, but mine was under warranty and the dealer is putting Mobil 1 in.

Guess the point here is to ensure that any oil you out in meets 5122 specs.



Also, another to consider is Liqui Moly from Germany:

https://www.liqui-moly.com/en/compan...over-2649.html

and from the UK:

https://www.opieoils.co.uk/pv-301975...20engine%20oil

 

Just another post filled with inaccuracies.

Oil weight is a factor of many things, from engineering tolerances to volume requirements, to of course any hydraulically controlled functions (not on the F-Type, but Chryslerand other use them for MD systems, camshaft phasing etc).

BMW M engines for example use higher weight oils, as high as 50.

In a lubrication system, oil temperature and PRESSURE are key consideration. The F-Type engines do a phenomenal job at keeping the oil cool. The oil rating is based on an upper temperature of 212 degrees, as that climbs and the oil drops in viscosity, so does the oil pressure. Likewise, an overly viscous oil will cause higher pressure than desired at operating temperature. 0W20 ensures easier starts (when cold it's 0). This also ensures that oil flows as quickly as possible to all moving parts almost immediately at startup (highest wear period).

Going to 5 is not ideal.... going over 20 should be only done when the oil runs consistently above 212 degrees (a temperature that the F-Type oil hardly reaches as it is).

I use Motul V300 0W20 on both my daily driven car and the race prepped ones with great results (and lower operating temperatures on top of it, 10-15 degrees cooler). This also reduces volatiles and crap going back to the intake....

 

Jag dealer installed Pennzoil Ultra Platinum on my last oil change there, instead of Castrol.
Service advisor said in over 20 yrs at various dealership service dept, he has never seen any engine failures from any cars that's has regular maintenance with synthetic oil, no matter what the manufacturer or dealer uses/endorses: Mobil 1, Castrol, Pennzoil, or even Dexos, etc. It's all good stuff & it's all marketing!

 

 

I always use what the company recommends. With the Corvettes and AMG's, it was Mobile One, the Z4 got Castrol, and the same for the F-Types.