The reason your dad might have changed his oil every 1000 miles could have been that your dad's car did not have an oil filter. I think it was first in the mid-fifties when oil filters even became standard on most cars. Hard to believe today.

 

Thanks for supplying an example of what I was talking about.

 

As you wrote it is what it is

 

Check out this Fact and Myth article from Castrol. Very good article

Castrol USA - Can You Handle the Truth about Synthetic Oil?

 

I can't imagine why Jaguar (and still puzzles me) would state that synthetic oil is not recommended. The simple fact is that synthetic oil meets and exceeds conventional oil standards, so you're only putting something that will please your engine but is better.

Quiet frankly, Jaguar can shove it. If my Mercedes, which obviously makes much [much] more durable and powerful engines, recommends Mobil 1 Full Synthetic (as with my previous BMW and SAAB), then it's what I'm using in my Jaguar as well. I've been changing the oil myself with Mobil 1 Full Synthetic since it had 10 miles, and 45K miles later, the engine is still running butter smooth.

 

There's nothing new or controversial in that link that hasn't already been thrashed to death here and on every car site on the planet. Aside from digging up a few dead posts from the archives, what is your message to us?

 

I had a long and sometimes heated conversation with the service manager at my local Jaguar dealer about the benefit of synthetic oil and regular oil in these engines. Jaguar in its owner's manual states, " the use of synthetic oil in Jaguar V6 engines is not recommended." In the supplement owners manual there is a short sentence which states, you can now use synthetic oil in Jaguar engines. But it does not say which engines.

The service manager, told me if you adhere to the oil change intervals on my 2.5L I will get better performance in the long run as the VVT in the engines do not work as efficiently with synthetic oil as it does with regular oil, and the crankcase with have to be twice as big as more synthetic is needed then regular oil to sustain the oil pressure I said how can that be, He said here read this document, which I did when I got home. Jaguar maintains to process the proper oil pressure so the VVT works properly mineral based oil can do this on less oil then with synthetic oil in the car. And as long as the change intervals are adhered to not damage will happen to the the engine. Also, the service manager said if you go to synthetic oil I should still maintain the engine change intervals as recommended by the factory which are based on regular oil. Don't extend intervals because you can with synthetic oil. I'll look around for that Jaguar document and try posting it perhaps this might settle part of this discussion. Personally I would rather spend $60 on a mineral oil change than double that on synthetic if the mfg of the engine says synthetic is not needed. Just follow the correct change intervals.

 

Interesting info Adam, although I don't follow the explanation on the VVT at all. These engines live very long and healthy lives on regular 'dino' oil, there's no evidence that this is extended through the use of synthetics. So, why bother?

 

I just changed my oil last week with Mobil 1 Synthetic and paid $70 for everything, including a K&N oil filter. I don't know why you are paying twice as much.

 

6 qts. Mobil 1 Full Synthetic is available for $22 from Costco every 6 months. Add a Mann-Filter for $10 and you're up to only around $35. You just can't argue against that.

 

I have used Mobil 1 synthetic oil in a plethora of different vehicles since it first became available. I also employed services of an oil analysis chemist that had statistics to clearly prove that nothing, but nothing, compared with the protection offered by synthetic oil. I was, therefore, shocked to learn that the maintenance supervisor at a Jaguar dealership said Jaguar DID NOT recommend synthetic oil except for the latest model XK8s/XKRs. This seems, similar to many things Jaguar, to be opposite of common sense and modern science. A definitive, scientifically based answer would be sincerely appreciated! Thanks!

 

Hi, Matt. My name is Joe (jhc on forum). I grew up near Lubbock. Wife graduated from Tech; I spent one semester there before moving on to different universities for undergrad & grad degrees. My old classmate, grades 1-12, is now the chancellor of the Texas Tech System. Saw him last less than 2 mos. ago there. My, how tech has grown! Chancellor is Kent Hance, BTW, and both of us went to Dimmitt Public Schools and graduated from DHS together. My current Jag, and I've owned 4 previously, is a 2002 XKR drophead, black on black, with about 31,000 miles. Just a toy.

 

Maybe Jaguar did the research that so many others haven't- despite the availability and usage of synthetic oils for decades, no one has been able to demonstrate that engine last longer or achieve any of the other promised miracles. As stated above, there's plenty of evidence that the engines live long and happy lives on regular 'dino' oil. If you know different, please share.

 

I would think Jaguar knows what they are doing when they recommend dino oil and not syn oil. The have engineers that study this stuff and I am sure they tested and retested before they made this statement. I run dino oil in my 2.5 and it runs fine. I change the oil and filter about every 4 months or 5K miles. Syn oil was original developed to help alleviate some of the oil crisis pressure on the industry, not necessarily to make engines run better and longer. I was told by my dealer the reason the use dino in the X engines is due to the VVT as the dino oil produces higher oil pressure then the syn at lower volumes of oil.

 

I certainly respect other viewpoints on dinosaur oil vs. synthetic. However, I had a friend, who unfortunately recently died, who for years was the head chemist for a commercial firm that tested oil for varied fleets: combines, tractors, semi tractors, cabs, marine, gas and diesel engines of all kinds. He told me that synthetic oils, particularly Mobil 1, basically had "rounder" molecules (in laymens' terms) and that the mere slick film of Mobil 1 on engine parts is remarkably effective, even if said engine were run without oil. Their company, preferably after day-1 of engine operation, took samples to analyize the initial microscopic metal particles and compared them to the varied metals used within each particular engine. So much steel meant this, so much cylinder lining components, so much ring components, and so on were present. Their business was to WARN fleet users when a specific rig was about to suffer damage, or had premature wear as it related to say, the number 2 cylinder bank, or whatever. Fleets learn quickly what to do and when to do it by this mode. My friend explained that nothing, absolutely NO other oil, could at that time be even in the ballpark of protection that Mobil-1 provided (in its correct viscosity). I even used them for my own vehicles that all were and always have been on Mobil-1 since the year it was introduced. I have had zero engine problems, period, since then. Now I do add this: Regardless of what Mobil-1 may advertise, I always change the oil and filter at about 6K miles, or less. I have a blown Hemi in one vehicle and I change it much more often, about 4K or less, because of the supercharger and the potential pounding forced induction may induce.

I also did quite a bit of research years ago on synthetics vs. dino oil and came up with the same ultimate results my friend concluded: If you really care about your vehicle you will use synthetic oil in every place it can go: engine, transmission, differential, transfer case, etc. There is one exception in what I've learned the hard way, if the engine is in a classic car, or an old British car or motorcyle (especially) you should not use it because of their inherently, notoriously poor, sealing jobs. (Why I went from a Norton Commando (sigh) to a Honda CB750 in 1971. I grew tired of cleaning up after them and pushing them. I'll bet from 1956-2008 I had pushed Brit stuff further than I rode 'em. You'll leak more oil than you can pour in. I also found, in my 1971 Mercedes Benz 280SE, circa 1972, with mechanical fuel injection (no auto computer adjustments, of course), that I put in Mobil-1 against the service manager's advice. I paid the price. The "idle" jumped from 500 rpm to about 1,000! Mechanical fuel injection requires careful surgical-like work in sealed rooms built to government standards regarding fire hazards. It isn't so cheap to have an old Mercedes mechanical injection system in the shop. New cars however----and I have at least one that even specifies Mobil-1 on the oil cap----that may NOT have synthetics from the factory (but I believe they do now), would not overrun idle as did my old 280SE as the new digital stuff would take up slack. (Ever notice how differently a vehicle may "feel," particularly in regards to acceleration positions of the throttle after your spouse drives her or his car almost exclusively? Happens at my house. I can hardly launch my wife's crossover without spinning out. She doesn't have that problem. The computer knows her foot!)

I also make some little exception with air cooled engines. In the last two HDs I had (2005 Special Edition Fat Boy; 2006 1200 Sportster, bored, stroked and all raced up. Went like hell but ate a valve (fixed free!)...a problem never encountered on Hondas and one Yamaha.) I used HD's hell-for-high dollar oil for air cooled engines, figuring they might have some metal innards in which only their brand of synthetic was acceptable. While I doubt that is true, and it's merely a sales gimmic, it could be. Some have suggested Jags had similar research. Maybe, but the main reason Jaguar has so long been in the hole, is Brown's Lane just doesn't make enough money for extensive research of this type; hence, the awful quality problems of any Jag until Ford washed their underwear. They still do odd things, though. Like put the cruise control off-on switch on the console with the remainder on a stalk, or a navagation screen that must have come from the old Lucas bin: Nearly impossible to see in the sunlight, and Lucas invented darkness, as any pre-80s Royal Enfield, Norton, Triumph, BSA, Matchless, Jag, Rolls or Bentley will prove about 10 minutes out of the dealer's lot even when new. I love 'um though. I must be a masochist.

 

No, just a little naive.

Let me cut/paste from this thread

https://www.jaguarforums.com/forum/x...oil-xkr-72445/

to save myself typing it all over again. Please read this post in particular:

https://www.jaguarforums.com/forum/x...45/#post507232

What you've posted is wonderful theory (that we've all heard a hundred times) but it simply doesn't translate into practice. Jaguar's oil change interval has been 10K miles/16K Km for many years, with a recommendation that bog standard dino oil be used. It is easy to demonstrate that the engines consistently live long and healthy lives, frequently outliving the vehicles in which they are installed as stated above.

It is impossible to state that a different product is better unless it can be shown that an equal size fleet of engines consistently lasts longer. No such proof exists.

 

@jhc

Your friend may have been stretching a bit. It is true that the base stocks of synthetics have more uniform molecules.

Aside from that, circa 2012, commercial fleets are still predominantly on conventional oils. They have not seen any compelling financially driven reason to switch.

As far as the ability of Jaguar, pre-Ford, to design engines ... the AJ6 in both the NA and SC versions are bulletproof.

 

Mickey, I am so sorry you are so sensitive on the subject. Often, when one stoops to name-calling, ie., "naive," it reflects an intrinsic fear of being proved wrong. You may be correct, I grant that, but I'll betcha' I've been soaked in Brit oil longer than you have been on the planet. I do read and open my mind to scientific tests, about which you are dead wrong: There have been such tests. It's much easier to put on blinders, step backward into the past, than it is to think. I'll not respond to any more posts on the subject. I guess there already have been too many. Scientific evidence is the answer. Thank you, though, for taking the time and effort to respond, even if you to hail me as naive.
jhc

 

Thank you for your observations. I, too, had outstanding luck with an XJSC six cylinder engine, and surprisingly to some, maybe, I had terrific luck with the DOHC 4.2 in a new 1965 XKE I bought. Sans fire extinguisher, however, I defer comments on the V12s in my life! Racing years ago also proved the robust nature of the 3.8s. It just was that assembly at the factory was shabby, engine sealing hadn't occurred to the Brits back then, and the ghost of Lucas plagued them.

 

when I was about about 12 or 13, my dad had a XK 150 for a while and as I remember it was a V12. I don't remember much about the car as I was away at school for a couple of years, my parents sent me to boarding school to make a gentlemen out of me, obviously that didn't work, so I came back to public school in town. Anyway, the X150, showed up one weekend at boarding school I was expecting them for the weekend an low and behold Pop drives up in a Jaguar sport car, He also had a Bentley, which he got for free, except for taxes, but that's another story. In the 150 I sat in between Mom and Dad. Again that was a very long time ago, but as I remember the car sounded bad, as the way the kids mean bad today, and it went pretty good. My Mom didn't like it too much she made him drive up to Ma with the top up and it was May and the weather was convertible weather. The car was black and had a beige interior, I forget if how many speed the manual trans had, it did have a radio and heater I remember. I got to hunt around their stuff and see if there is any pictures of that car still around. I put it in the copy machine a pic of the Bentley I found, to create a file pic and the pic was so brittle it cracked into a punch of pieces from the heat I guess from the printer. But as I remember I was the hot **** of the school, even thou most other Dad's had caddies, olds, buick's Mercedes Benz, one had a 356 I remember. But my Dad was the car king of that weekend.

PS: Ironic that 50 years later I got a Jaguar for myself. I never had much interest in Jags except the XK and XKE, but never bought one, but when the X type came out I fell in love and finally found a decent one. Oh when I came home from school that summer the XK was gone Dad sold it as Mom did not like rag top, Even thou the Bentley was a rag top also but she said the wind didn't blow on her as much as the Jaguar.