"jaguar engineers" is this an oxymoron? funny, some parts and designs are brilliant while others you wonder if the night janitor was playing a joke on engineering plans. UGH

 

No offence taken at all I assure you.

As nerdie or geeky as it sounds, I take personal interest and pleasure in the general subject. The latter part of my long career at an aviation engine OEM was spent in tracking, correlating and reporting reliability and durability data to the various federal regulatory agencies around the world for certification purposes. If we think that the end retail customers (us) are a 'tough sell' when it comes to breaking with age old tradition or parochial thinking in maintenance practices, they've never dealt with Transport Canada, the American FAA or the British CAA in terms of being conservative.

Despite mountains of data demonstrating what happened during in-house testing and that it matched precisely what the engineering folks had predicted would happen before the first real test was done, the only thing that really counts at the end f the day is field experience. This is the point being made here: Jaguar says that the engines will do just fine on oil type X of viscosity Y if changed at interval Z. Field experience appears to demonstrate that they were right.

Let's take the ubiquitous Chevrolet small block V8 for a better example. It's been around for more than 60 years and hundreds of millions of them were built and operated in every climate on every continent on earth. There's no shortage of field data to back up just about any claim that someone may want to make.

What stands out is that in spite of abuse and neglect by some owners (as opposed to O/C care by others) the engines typically last 'Z' interval between overhauls. This interval is large enough that it exceeds the expectations of the owners, or the life the of the car itself and as a result gains the reputation of being an excellent product.

Another element that stands out is that despite the advent and common usage of synthetic oils, there has been no real change in interval Z over the decades. IOW, they last no longer now than they did back in the 50s.

Why? It's not due to any shortcoming of the oils, it's simply because the engines typically require overhaul for reasons unrelated to lubrication.

It becomes difficult then to sunstantiate the usage of a more expensive product promise of 'greater engine life'. Synthetics are superior when it comes to oil change interval, but most Jag owners won't even make use of the factory recommended interval for dino oil, never mind extended intervals with another product.

 

Well said. I agree.

When it comes to oil, I am most impressed by the bearing tests and cleaning ability of oil.

 

It is hard to break from the old 3,000mi change interval wisdom passed down to us "car nuts" who like to think we're taking care of our babies better. I change mine out with the recommended grade when I store the car every year for 5 months. I do the same with my boat and mower, just to have acid-free oil in there. Works for me. I've never had the chance to exceed the milage/hrs interval recommended by the engine manufacturer, but I wouldn't. Thanks for the OEM perspective. That's why I follow the service manuals on all my stuff. I don't want a failure to be my own stupid fault. Enough stuff manages to break on its own to keep us all busy.

 

I use synthetic 5W-30. Synthetics are better at resisting high temp breakdown than standard oils. In a supercharged engine, I consider a synthetic as a requirement, not a suggestion. Oil temps are higher in these engines, especially if the driver uses the capabilities some. When I look in the oil cap, I see an engine that looks like the day it was built, totally clean. I like knowing that the passages and parts are working in clean oil. As much as it cost to run one of these cars, keeping the lubrication at the top of the game helps keep things working right. I also changed the tranny fluid at 50K, it makes a noticeable difference.

 

Absolutely. I worked for many years with a major oil company, formulating and testing lubricants among other products. Synthetic oil IS different, does not break down nearly as fast as mineral oil, has superior viscosity properties, allows longer times between oil changes and, most important, does not tend to carbonize as quickly as mineral oil. Why would this last point be important? Oil is also a coolant, and stops circulating when the engine shuts down. Supercharged and turbocharged engines will retain a lot of heat if the engine shuts down after a hard run, and there is an increased tendency for ordinary oils to coke up in the turbo galleries at that time.

 

THe supercharger in the XKR does not use the engine oil for lubrication, it has its own lubricant, a type of jet turbine oil.

 

Right- which is why the elevated temp capabilities of synthetics are of no benefit (ie wasted money) in our engines.

 

Mikey,

I can't get too excited over 'best oil' debates. The worst that can happen is my engine seizes and:

1. I pull over to the hard shoulder
2. get towed
3. replace it
4. back on the road again

Your line of work is a different game altogether. I'm very interested in the reliability of the engines in any aircraft I happen to be in. Don't go sick or cut off early on a Friday! Failure in that scenario from 30K feet doesn't let me get me past step 1 above.

Graham

 

Hi Graham-

I should stress that me skiving off is of no consequence to the flying public for two reasons

1) I've been retired for three years+ and left some very competent people in charge when I moved on. These people endure the same regular thrashings from the regulatory authorities that I formerly enjoyed, sometimes with extra helpings on holidays.

2) aircraft and engines are reliable in spite of people, not because of people.

The same holds true for just about any mechanical device- the human element is usually the weakest. No matter what the OEM can dream up as a torture test, field experience will reveal all sorts of new ways of pushing the limits. Without sounding pious, there are several factors that drive OEM nuts

-owners that don't read the manual (RTFM!)

-owners that RTFM but feel the need to second guess 'cause they know better' and have dreamt up a nasty conspiracy theory as to why the OEM specifies doing things a certain way.

In the case of our cars, it's well known that the engines last an extraordinary time span if the manual is followed. There's a small amount of data that suggests that they last a long time even if abused. There's no data (just theory) that they last longer if pampered with fancy boo-teek oils. On the other hand, there's no data that indicates that they suffer any harm with such oils.

As always it comes down to using whatever makes the owner happy.

 

Yes, I find some of the, I know better, modifications people do to their cars most puzzling.

But then they are theirs to do with as they wish, as long as they don't blame the OEM when things go wrong!

 

The stories I could tell................

 

Mikey, I really don't believe that is so for turbocharged or supercharged engines. Jaguar recommends Castrol, and Castrol recommends synthetics for high-performance engines. The extra mileage between oil changes alone makes it worthwhile, never mind the near-elimination of sludge due to improved stability at 220-240 F.

Oil companies do more research on engine lubrication than anyone else, but they don't always publish detailed results. When you say "there's no data to support...", that means you haven't seen it, not that it doesn't exist.

Anyway, as Stumpy has noted, it takes all types. What the hell, I hope you enjoy a long and prosperous retirement. Me, I'll stay with synthetic oil.

 

The discussion can go on forever, but I'll leave this with these last comments- the oil companies are #2 in the amount of research done on engine lubrication. The engine OEMs are number 1 as it's their name on the car (aircraft nacelle) and their warranty dollars when it all goes wrong. Jaguar designs and builds the engines and Jaguar makes no mention of requirement for synthetics.

 

Hi all,
New 2000 XKR vert owner. I was putting to many miles on my 03 Corvette. So I went looking for a DD to use. When I starting looking at the XKRs. Found one on EBay put a ridicules low bid on it , and all be darn if I didn't Winn it ($7500.00). Jaguar is in almost perfect condition ! Just high miles at 117,000 miles. Perfect for a DD!! After getting it and driving it for 2-weeks now I'm starting to fall for it...lol... The cover on the Vette hasn't been off for 2-weeks now..lol.. Only complaints is the Jaguar is black ext. with black top, love the two tone tan interior!!! Anyway my question to all is the Jaguar didn't come with any owners manuals. So I want to do a service on it, engine oil, supercharger oil, trans fluid. The water pump was just replaced and coolant flush done 2-weeks before I bought it. This is the first supercharged car I have owned. So by reading on here I see it has it's own oil(where do I check it at, how often should I check it)
So to the root of my question. What is the OEM recommend fluids, how often for
Engine oil
Supercharger oil
Trans fluid
Brake fluid (DOT 3 or 4??)
Rear end fluid
Antifreeze
Am I forgetting any...lol...
If I should start my own post just say and I will! Just figured this was perfect group of owners to ask..
Thanks for any and all help!!!!
Robert

 

Forgot to mention I live in southern AZ. Very hot summers (yesterday was 102 here, we do see some snow during winter, never last on ground for more than 72hrs. I live in foothills at 6200ft.
Thanks, Robert

 

Welcome to the forum Robert,

Once you been here for 3 days AND have a minimum of 10 posts, you'll be able to download the full set of manuals from this link:

https://www.jaguarforums.com/forum/x...-2003-a-67827/

One way to get towards the necessary number of posts is to go to New Member Area - Intro a MUST and tell all the members about yourself and your XKR.

Graham

 

Thank you,
Yes I just found, the manuals. This forum is different than the corvette forums. But at least it's free!
Robert

 

Hi Robert- welcome to the site from a fellow Jag and Corvette owner. You're best off starting your own posts and don't forget the new member's area as suggested by Graham.

 

I agree with everything the Dr said but would comment as follows:
In relation to oil pressure/ flow it is a given that flow is essential but pressure must not be overlooked for example a car with worn big ends will let any given viscosity of oil flow more readily through the bearing than a similar car with no wear and the lower the oil viscosity the more still it will let through. As the oil is let through the worn big end bearing it reduces overall pressure. Remember the oil must have sufficient pressure to force its way into journals and bearings etc and in some engines to operate valve lifters. Without pressure the oil simply wont make it to everywhere it is needed, that's why cars are fitted with pressure operated gauges or warning systems. Increasing the viscosity of the oil reduces the effect of wear by slowing the rate of flow through worn big end bearings and subsequently raising overall pressure and hence flow to other parts of the engine.
A warning however, too viscous and oil and the pressure can be dangerously high, many wonder oil additives act to increase viscosity which in turn raises oil pressure but I have seen the result of over keen application and an oil pump which had raised so much pressure internally it had split the metal pump casing wide open, the oil in the sump had so much additive it was literally like treacle.
In short consider the mileage in your engine if it is low then the recommended less viscous oil, with a higher mileage engine move up a viscosity. If you look at a Jaguar handbook it gives a range of oils by viscosity for any given engine. Use an oil within these specs, with an eye to engine age. mileage and use. Personally on a 100k XK8 I am running a semi synth 15/40 with changes every 5k or 1 per year. The engine runs sweet and quiet.