[QUOTE=Rambunctious Jaguar;964439]Also use the t6 5w40 and have had no issues with it! So I would venture to say that your ticking is not oil related rather mechanical wear!

 

Quite possibly, the Mobil one feels good, I've moved on, I have a new concern with a slow coolant leak which i believe is coming from behind the engine/before the transmission pan/filter area

I will not to return the coolant !!!

 

Since I could not get the recommended Castrol oil ( SLX Professional Longetec A5) and not willing to throw $250 for oil change in the dealership - I had this one put in:
LIQUI MOLY - Motor Oils, Additives, Car Care - Products - Longtime High Tech 5 W-30

Supposed to be even better than original... German made... We'll see..

 

Jaguar makes no mention of this particular oil in the owners manual. Here's what's they do specify:

"Oil specification – API SJ/EC and
ILSAC GF–3"

followed by

"SAE Viscosity Rating
For climates ranging from –22°F (–30°C)
and +122°F (+50°C), the following oil
viscosities may be used:
0W–30
5W–30 (preferred)
0W–40
5W–40"

Any brand of oil meeting the above spec and viscosity can be used. There is also no requirement or recommendation to use synthetic or semi-synthetic oils.

 

I know Jaguar says that, but still...

There's no question that synthetic oils can cope with a bigger temperature range than conventional oil. Just look here:

https://www.google.ca/#q=synthetic+o...-3%3B600%3B387

... and the viscosity of synthetic is more stable as the oil ages.
... and the mileage interval between oil changes is greatly increased.
... and my STR has no fog lamps because they would block air to oil coolers!

So, what the hell - I always use 5/30 synthetic oil.

 

Except that our engines never come close to the thermal limits of regular dino oil so the extra headroom of synthetic never comes into play.

... and the viscosity of dino oil stays stable enough to warrant a 10K oil change interval
.... nobody I know with an S-type goes more miles/KM on synthetic than dino or has any idea what's 'safe'.
... if the reason that the -R has no fog lights is strictly for oil cooling- why did Jag not specify synthetics?


As always- use it if you like it but let's not pretend that the cars care one way or the other.

 

My engine runs at over 210F, the thermal limit of conventional oil looks to be just under 200F - what do you mean by "never comes close"?

I would suggest that Jag did not mention synthetics precisely because fog lights were not fitted. But I am thinking of fitting fogs, so am looking for as much thermal headroom as possible.

 

When i was at the dealership last week , I began conversating with the individual helping me stated that Castro was specifically made /forrmlated for jaguar. I'm unaware of this, however, I do recall my manual having a castrol logo where engine oil viscosity is addressed. He also stated something along the lines of using castrol synthetic within his own s type, and only using it...

 

Conventional oils are tested at 302*F for thermal stability as part of the API certification process. No idea where you got under 200*F- that's less than the boiling point of water.

How are you measuring oil temp in your car?

 

Castrol motor oil is not specifically formulated for Jaguar. But Jaguar and Castrol do have a business relationship that has been ongoing for many decades. I believe that Toyota and Castrol have had a similar business relationship since the 1980s, just not as symbiotic as the one between Jaguar and Castrol. I use Castrol 5W-30 conventional oil in both of our Jaguars because it is indeed a good product and I buy it at very good prices when it goes on sale. But I would not hesitate to use any decent 5W-30 conventional oil in either of our Jaguars (I also like Valvoline and Shell)....

As has been stated here many times, just follow the specs and use what makes you happy. There is no legal requirement to run any specific brand....

 

The following reasons that you should be using Valvoline (dino or synthetic) over Castrol are at least as valid as any Castrol justification given above, if not moreso:The following is the reason I've been using Castrol in our S-type 3.0L's in lieu of Valvoline:I've been using T6 in the Excursion and X300 for a number of years. It is great stuff and considerably cheaper than the Valvoline or Castrol. Even so, I'm quite dubious that Rambunctious obtained enough T6 for a proper change in an S-Type, for $22+ though I may be wrong - The 3.0L takes 7 qts. surprising if the 4.2 would be barely over half that...and a 4 qt jug is $21.50 in here in TX (+tax, of course) A Castrol Jug is 5 qts; I've never seen T6 in that size.


Prior to this thread popping up I'd been considering shifting to T6 fleet-wide to reduce complexity - even had #1Son use T6 in the 03 F150 when he was doing a change while home for spring break a few weeks ago, having become persuaded Ford's recommendation of 5W-20 is based more on fuel economy concerns than engine longevity. This one pushes me over the edge to make the switch - and the 05 is due, so I guess I better get out there and check stock on the Castrol, see if this is the point to make the switchover or maybe in a few weeks when the 03 returns and is due...
Why not Valvoline Syntec 5w-40 in lieu of T6? See reason for using Castrol in the S-types above

 

I purchased each jug for 22 bucks and each jug is 4 liters, my 05 n/a 4.2 requires 6 liters

 

Everything degrades faster at higher temps. High-temp testing is used in order to get an answer in hours, not days or weeks as would be the case at lower temps.

Normal-condition operating temp for motor oil is under 200*F, according to the chart in my earlier post. Even at that temp the oil is still degrading, but at a slower rate. And regular oil faster than synthetic.

In the absence of an oil temp gauge, I assume the oil temp does not exceed the temp of the surrounding coolant. That is, until I instal fog lights and partially block the oil coolers.

As far as I'm concerned, engines do care one way or the other. It's only some owners that don't.

 

Sorry, my bad. While the above posts don't exclude the purchase of multiple jugs, they certainly don't indicate such, either. Meanwhile, they DO indicate an admitted lack of knowledge on your part regarding 4.2L oil capacity..
I guess I should've expected it, after being presented with the "green flushless urinal" at the San Jose airport last time I visited the Bay Area - an "advancement" that seemed to operate on the same principle, and smell remarkably the same, as my grandfather's outhouse in the Appalachian region of Eastern KY. Still, I'm nonetheless distressed to learn CA, perhaps previously synonymous with establishing the automobile as an icon of personal freedom, has now gone full Euro-Commie and is peddling motor oil in Litres.....


T6 purchased in the free Republic of TX boldly state: 1 US Gal (3.875L)

 

There was no chart in your previous post, just a link to a Google search.

Engines consistently outlast the rest of the car they were installed in despite the shoddy practices of most owners. Look in any scrapyard.

 

Hey Mikey do have a stable for that high horse of yours ??

 

Make it easier Mikey, just check this S-type forum. I'll bet I can find 3 threads from members who have blown their engines in the last 12 months. But then, you are a Coordinator, so you already know this.

Scrapyards usually consist of cars written off in accidents. I don't recall seeing a working engine surrounded by a pile of rust.

Other than the need to mount your high horse, what is your real objective here? Straight answer please.

 

Hehehe..

 

"The truth"

and not continuously attempting to turn simple, routine subjects like oil and fuel into pseudo rocket science by pretending that these cars are some exotic, delicate flower that needs daily white glove care.

Let's also not pretend that any us have enough knowledge or are smart enough to correctly second guess the OEM. If Jag says 'use this' and sells a car with a decent guarantee behind it, that's pretty strong evidence that they know what they're talking about.

Please leave the conspiracy theories at the door while we're at it.

Let's at least make a decent attempt to separate science from marketing material.

Of the engines that we've seen that have grenaded, at least half were running synthetic oil. More importantly- how many of them failed as a result of lubrication issues? Why are there no stats anywhere on any car that indicate a lower rate of engine failure while using synthetic over dino? If there was such a trend, why would the OEMs not have made a wholesale switch years or decades ago?

If you are truly convinced that synthetic oils are required to ensure decent engine life, I'd suggest you contact the engineering dep't at Jaguar to inform them of their blunder.

BTW- I did a little research about oil temps. Seems that there's many many cars that routinely run at 220-230-250*F on a continuous basis. This is not something new or is restricted to 'exotics' - it's always been that way. Any car I've been involved in operated with higher oil temp than coolant temp. Most engines run at a minium of 210*F oil temp and are not considered to be fully warmed up at anything less.

That sort of flies in the face of your findings inferring that things go south at less than 200*F.

 

There's been mention of a few (3 I think) STRs that have thrown a rod. Never heard any claim it was due to failing to use synthetic or other oil-related faux pas. Jaguar say non-synthetic and 10,000 miles, so that's got to be "good enough". Use any other oil or service interval at your own choice, guys. If you've hard facts relevant to the engines/cars we have I guess post 'em if you like.