See your handbook. (Can be fetched free from jag's TOPIx.)

Looks to be like mine WSS-M2C913-B 5w30. I think there's an updated spec for the WSS-part if you care to hunt.

Jaguar have a deal with Castrol which can make it seem like that's what you must use but that's not true. The spec is what matters.

 

Yes, it makes all the difference in the world. Here's what the owner's manual says for your car

"Engine oil specification API SM and ILSAC GF-4.

When topping up between oil changes, make sure that you use oil that has the correct quality level (API service) and viscosity grade. Note: For maximum fuel economy, 5W-30 oil is recommended. Engine oil temperature ranges For climates ranging from - 35°C (- 31°F) to + 50°C (+ 122°F), the following oil viscosities may be used: 0W-30 will protect from - 35°C (- 31°F) to + 35°C (+ 95°F). 5W-30 (preferred) will protect from -30°C (-22°F) to +35°C (+95°F). 0W-40 will protect from - 35°C (- 31°F) to + 50°C (+ 122°F). 5W-40 will protect from -30°C (-22°F) to +50°C (+122°F)."


You can use any oil that meets that simple spec. Many of us long time 4.2 owners use what came with our cars when new- which was non-synthetic 'dino' oil.

Think I'll don my flame suit now.

 

]QUOTE] You can use any oil that meets that simple spec. Many of us long time 4.2 owners use what came with our cars when new- which was non-synthetic 'dino' oil....Think I'll don my flame suit now. [/QUOTE]

LOL. Yes, there are some flame throwers out there ready to scorch your rebellious behind.

I do think its a worthwhile discussion, as some are unable to obtain factory spec oil except by begging at the gates of Lord Jaguar's Castle. On the other hand, at least we're not addressing the advocacy of STP or Marvil Mystry Oil.

 

Indeed. And thanks for the informative post above.

I couldn't find anywhere that says WSS-M2C945-A replaces WSS-M2C925-A. Do you have a source? That would be great if so. My dealer's service manager provided zero help when it came to oil alternatives. Maybe we should write to Jaguar.....

Also, I've used Mobile1 almost exclusively in all of my and my family's vehicles (auto) for 35 years. probably 500,000 miles. No problems. Can't be that bad

 

I think this is a mistake on my part. I read it, but not from a qualified source. He was saying the 925 was a spec that Ford no longer uses, but Jaguar does. Link here in Bobistheoilguy. > https://www.bobistheoilguy.com/forum..._STJLR.51.5122

I made the assumption that both specs are included in many brands and are certified to meet both these standards; but its not correct to say that one was usurped by the other.

I would like to add that if I continue use the Castrol Edge Pro, it will be due to lack of knowledge, not paranoia created by Jaguar's agenda marketing their dealer service.

 

As part of the science you must question the psychology. (I did mine and was shocked when I pressed myself for a truthful answer)

Here is the test question:
Jaguar got an oil company to design an oil just for them.
Jaguar designed some patented and revolutionary oil strategies. (Even Ford licenses this patent from them)
Jaguar made this oil available to you at the same price and in most cases cheaper than premium oil brands, Amsoil, Royal Purple, Red Line.
Unlike others, Jaguar certifies that this oil will give you no trouble.
Jaguar proved themselves over time not suffering carbon buildup problems
You ask there has to be an alternative.....

When I lived where you do now- everything was inconvenient- going to the museum, opera, taking an international flight or even fine dinning required a 3 hour round trip. And my exotics back then were incapable of a 3 hour trip. Even commuted to daily. You are calling the once a year pilgrimage a chore.

 

Ah, thanks. I thought you were on to something

I will continue to have the dealer do my XK just to get the right oil since it's relatively convenient and that's ok with me. I still have 3 other cars and 2 motorcycles I can do myself

 

@ Q&C: Before I moved to Daytona Beach Florida, I lived for 30 years on E89th/Third in the heart of New York City. Where going to the museum, opera, taking an international flight or even fine dinning required but a simple 15 minute taxi ride. Now I like it better here.

And I've already addressed the 'pyschology' of the issue, which is that Jaguar and Castrol are in cahoots w/ each other for financial gain, not to guarantee owners the expected useful engine life of their automobile; and certainly not to please out-of-warranty owners who would sully the ownership experience by doing something so plebeian as changing their own oil. But thanks for the back and forth on this topic. It's so nice hear from an owner with the old world charm of the mother country.

 

Absolutely not. Like I said the hardest thing in this world to do is admit one have come to a conclusion based on personal emotion. If we logically deconstruct it you wont feel insulted at all.

What research or empirical data do you have to support your claim? You barely even know what oil to use, and definitely not the reasons why you should use it.

I have 3 pieces of data that might convince you that you should question your thinking.

At $30 a quart, there isnt enough volume from Jaguar sales to even pay for the R&D on the dye.

Other companies making this grade of oil sell it for more than you paid- go figure. And they wont even sell it to you. Try it, talk to the top brass at Motul.

Here is a video of Castrol Magnatec (cheap synthetic) vs Castrol Edge (premium Synthetic)

Here Castrol (our oil) vs BMW (more money)

 

I have an opinion on why both Jaguar and Castrol have attempted to make it inconvenient and expensive for consumers to obtain the singular specified oil for their cars. You have your opinion on that matter; I have mine.

I never said any oil will do. But I did say I believe Castrol and Jaguar have colluded for mutual gain. Why is that so difficult to believe? What other logic do propose that would make it nearly impossible to buy the correct and approved oil except through Jaguar dealers? They're certainly not doing their customers any favors here in the US by monopolizing the retail sale.

 

Wow, you totally missed the facts and opted for your opinion. Which is what I was trying to help you with.

You have built a mountain on 2 absolutely false assumptions.

1. This oil is expensive- its NOT, its less money than anyone else making this oil. Have you seen how much the Motul or Mobil cost??

2. Jaguar has conspired to make this oil inconvenient to obtain- Again very wrong. Its a Ford spec and you cannot buy this oil from all the other people who make it including Mobil!! Jaguar sells this oil to absolutely anyone who wants to buy it at any Jaguar service station.

Its not a matter of opinion. Just black and white facts.

 

Incidentally, note to all.

If you believe that Jaguar and Castrol have colluded for financial gain....

Think it through- is there really any money to be made by supplying a handful 5.0 jag engines- 80% of who go to the dealer anyways?

Or is there more gain in making sure a $14,000 engine doesn't come back with warranty claims?

If you answered more money by selling oil to handful of Jag enthusiasts, then answer the subsequent question.
Why does Motul not make a fortune by supplying their version of this oil to this lucrative market??

 

Well by the tone of your reply, you seem to think I'm either 1) cheap or 2) ignorant. I think I'll take door number two.

1. I quickly found Motul specific 948B 5W20; 5 Liters for $48.28 or about $9 per quart; Mobil 1 routinely sells for $6-7 per quart or less. I paid $12 a quart for the Edge Pro, which is not an outrageous difference (and certainly one that I can afford). However, the price differential is still on the order of 50 to 90 percent more than the brands you cited. I'm not sure what your personal benchmark for 'more expensive' is, but something that costs half again as much qualifies as expensive to me. Clearly if your ONLY recourse is to have a dealer change the oil for $200 or more, then that IS expensive.


2. If Jaguar and Castrol are not in collusion, Why is Jaguar the only authorized outlet for this single Castrol product? Other Castrol products are readily available everywhere. Explain to me why you can only get this one product from Jaguar dealers.

 

Thanks GC for not taking it personally. We have all gone through exactly the same considerations as you. After months of research realizing the brilliance of the engineers and the ignorance, pettiness and arrogance of mine.

Motul and Mobil are not even available in this country.
Why is jaguar dealer the only place you can but this oil?..for the same reasons that Motul and Mobil dont even bother selling it at any outlet in this country- its not worth the effort!

 

Whatever... They could sell it on Amazon and make everyone happy.

 

BTW take those guys on Bob is the oil guy with a grain of salt. They havent a clue in most cases and do not have your car.

They moronically believe thinner oil is for better fuel consumption and to help with start-stop engines.

First of all, Jaguar did not go to a thinner oil- it is only thinner on cold start. Soon as the engine warms its the same as their older oil, or indeed the oil used in truck engines.

So that tells you what problem they are addressing. Oil flow at startup critical to cam and timing chain tension. Also massive amounts of new studies have shown in DI engines oil thickens due to soot.

 

OK Q&C. Thx for the headsup. Bye for now.

 

Wow. More nonsense in our conspiracy-prone world, where everything, even the oil one buys, is a get-rich-quick scheme. Of all the things Jaguar corporate could profit from, oil gouging, quart-by-quart, would seem to be something the Trump offspring would conjurer up. A low-rent, cheesy con easily discovered and difficult to wash one's hands of. I use to hear this same concern over Harley oil, especially in the days of the venerable Shovelhead. Turns out, the HD oil actually reduced harmful sulfur contaminants...if we walk this dog backwards, one might imagine Jaguar corporate is doing what it can to project the perception of a dependable and reliable automobile in a time when even the cheapest car easily sees the far side of 100,000 miles. And maybe this is the real advantage of owning a car built without bending to all the bean-counter restraints. $100K buys a lot less compromise. An at $300 an oil change the dealer already has his hand deep in my pocket. Do I really believe he's going for another two or three bucks?

 

While much as he's great, Q-and-C can be a little strident in his responses- but in this case his logic is spot on.
Think of all the oil, in all types and capacities, that Castro sells worldwide.
Do you actually think Castrol thought: "we've got to get in on that JAGUAR XK DIY MARKET!!
Jaguar sells HUNDREDS, maybe THOUSANDS of XK's a year!! And that means DOZENS of owners who change their own oil!! We gotta GET THAT! GET THAT!!"
I mean, come on.

 

Wonder if the conspiracy theorists realize all conspiracies or just the one that supports them. The other conspiracy is that we all want service-free cars and multi-million dollar service centers..are we willing to give two or three bucks to the cause, or drive there in our grand tourer.

You should post more often. Enjoyed the read.