Yes indeed Sparky..The original question as I did address was that OIL Viscosity is an engine design requirement and NOT to save on gas...or to keep it simple for some people, not to improve fuel economy or get better mileage...So it is important to stay with the recommended weight or viscosity. CAFE has not a damn thing to do with what type oil viscosity to use...CAFE is a campaign to get auto makers to make more fuel efficient cars..PERIOD!~

Yet somebody wanted to raise their rooster feathers, to show he is the big **** of the walk and prove me wrong by implying I said something different..And Got into his Star Trek fantasy...Hence then the silliness

 

:ico n_deadhorse:

 

But it does have something to do with how to read the most
common document owners use to determine oil viscosity ...
the owners manual.

What CAFE does is mandate that the recommendation printed
in the owners manual be the oil used during mileage rating tests.

Therefore, a manufacturer who decides they need to use 0W20
to achieve their CAFE goals can only publish 0W20 as their
recommendation. Now, if engineering said that 5W30 will
prolong the life of the engine past that under 0W20, that's
just too bad. 0W20 is the only number that can be published.

The manufacturer never has to disclose such data. They only
have to toe the line on exactly what the regulation demands.

The regulation is not imaginary or opinion. It is available for
public inspection to anyone who cares to read it.

 

Obamacare says you must have Health Insurance..but it doesn't say what Blood type you must have...same thing

 

At the risk of starting another frustrating discussion board oil thread; modern synthetic oils protect much more effectively at lower viscosity ranges than old school oils. That, and modern aluminum engines have tighter clearances, piston cooling jets, etc., requiring lower viscosity oil at higher flow rates to maximize engine reliability. This is especially true during start-up periods.

 

Heresy!!!

 

Thanks. I think I will agree with you and run the castrol SLX 5w20.

Well it just seems very low viscosity for the power output. 510hp in a 5800 pound vehicle I would assume would use 5w/40 or 5w/50.

I am under the impression that although in other engines heavier engine weights are advised for rough conditions that is not the case with Jaguar Land Rover AJ133.

Another thread on here indicated that Jaguar said the timing chain tensioners are influenced by oil weight and high oil weight can cause the chain to skip and blow up his engine?

 

I think you're making a few assumptions and statements that I don't quite follow. Oil viscosity has little to do with horsepower, vehicle weight or operating conditions other than ambient temperatures.

You may wish to do follow some threads currently running about the 5.0 DI engine and potential premature wear.

 

OK if there was no correlation we would see 100 hp light duty engines run 0w40 or 0w50. Since if your statement is true then the contrary is also false.

Do you think trucks as an average use higher weight oils than cars?

Or how about the hellcat which specifies low weight oil unless you are racing?

 

Not really interested in a debate.

Comparing two different engines (truck vs car) is apples and oranges.

Racing vs. street use is also apples and oranges.

 

Come on Mikey, I really need to see another oil weight/change interval discussion. I haven't seen enough of them in the 3 years I've been a member

 

I'll sit this one out. My typing fingers are still sore from the last few.

 

Actually it is the same engine in the xfr as the range rover 5.0sc. Aj133 so it is apples to apples. I guess as you would say.

 

I have recently concluded that the most reliable indicator
of engine protection vis-a-vis engine oil is HTHS viscosity.

One way of saying it is that HTHS is the effective
viscosity regimen seen by the bearings and rings.

ACEA A3/B4 stipulates a minimum of 3.5 over the
life of the oil.

Most HDEO HTHS measures are north of 4.0 in real life.

It so happens that the usual argument for xW40
happens to be a proxy for the underlying HTHS.
Hence the observed excellent results for proponents
of xW40 HDEO such as Rotella. Even the old adherents
of Castrol GTX 20W50 were on the right track.

However, HTHS is a direct measure, and there has
even been a peer reviewed and widely accepted
formula that shows the relative wear relationship.

Multiple studies, including SAE conclude that HTHS
under 2.x coincides with increased wear. x because
I cannot remember, but I recall 2.6

A 0W20, by definition is 2.9 or less due to the 20
part of the designation. SAE says so.

Anyone wanting to spend 10 or 12 hours reading the
pdf's can find them on a search engine the same way
I did:

optimum hths engine oil wear rings bearings

No, I will not "cite" them. Go look.

I have two jugs of Castrol European 0W40 ACEA A3/B4
in the trunk which are going in tonight.

Oh yeah, some light reading for those who cannot spare
more than 15 seconds:

From the trade rag Machinery and Lubrication

Motor Oils - Fuel Economy vs. Wear

Motor Oils - Fuel Economy vs. Wear

++

 

At least it's not a debate including Jagular. Those could go on for months! Although to his credit, he certainly contributed to the forum with objective content. The subjective topics got pretty interesting though.

 

To me a 'truck' has 18 wheels. My truck and SWMBO's truck (your definition) both use the same weight oil as my cars.

 

Had me wondering until I noticed the extra "L".

I will say though that at least on other automotive
forums, the participants seem to be at least willing
to make forward progress on the technical side
rather than throwing banana peels.

 

You just defined a truck so narrowly no one would agree with that definition as it doesn't include common trucks such as dump trucks, fire trucks and Motorcoaches

 

I imagine quite a few people are or shortly will be out of warranty for their engine and could care less about CAFE (USA only?) so would probably like to know the engine oil that will best protect their engine. I am guessing that car makers (including Jaguar) don't say, other than a reference to their published spec such as the handbook.

Now, the car makers don't want people suffering early dead engines as that'll kill sales, so the handbook oil spec can't be too bad. (OTOH it may not be the best oil at all.)

I suppose about 8-10 years and 100K miles or so is about the minimum an engine needs to last to keep a car (well, engine) maker out of getting a bad reputation (pick your own # years and miles).

If there's truly a problem with the 5.0 SC engine in this thread, in terms of chain etc, is oil the way to fix it? Does it fix it? Is it the magic Castrol oil Jaguar apparently push & sell? If the fault(s) is/are real were they known about in time for Jaguar to recommend that oil?

Would 5w30 as in this thread be better or worse and why (forgetting warranty, CAFE, etc)?

I'd quite like to know (I'd be more interested still in my car's 4.2 SC engine!) but these may well be the wrong questions and of course oil threads do tend to drift...

 

Your car, your engine, your choice. But if you have engine problems and you're still under warranty, using any oil other than what is specified by Jaguar in the Owner's Handbook can result in your warranty claim being denied. See Regional Coordinator Mikey's Post #8 in this thread: https://www.jaguarforums.com/forum/x...estion-107516/


"Quote:
Originally Posted by chazaroo
here is a extract from the Jaguar training newsletter regarding Castrol. Looks like using anything else could be a warranty problem. Brilliant cash hustle by Jaguar.:

· Stable viscosity for sustainable performance
· Improved engine cleanliness and engine protection
· Better ability to compensate for various driving styles

There are several features your new Jaguar customers should know about:

· The new Castrol oil, SLX Professional 5W-20, is the only oil recommended for the new 5.0L AJ V8 engines
· A service reminder in the Message Center lets the driver know when it's time to change oil
· Service Interval is every 15,000 miles or 12 months, whichever occurs first. It's important that your customers visit your Jaguar dealership yearly for annual service
· The first scheduled maintenance service visit is Complimentary
· Maintenance Interval Message automatically appears when it's time for service
· Checking the oil level is simple using the built-in "digital dipstick" on the car's onboard computer. The new engine does not have a traditional dipstick

The Jaguar/Castrol co-engineered 5.0L engine 5W-20 synthetic motor oil is the only lubricant completely tested to be compatible with Jaguar’s new engine components and other fluids and sealants. No substitutions should be made as the warranty coverage requires the use of the proper Jaguar specified lubricant.

The devil is in the detail. There's a difference between 'specified' and 'recommended'.

Jaguar 'specifies' lubricant that meet WSS M2C925-A and they 'recommend' Castrol brand. You're free to choose whatever brand that meets the spec.

Yes, it's slimy doubletalk."

To me, it makes sense to use only the oil specified by Jaguar. Otherwise, you have no recourse.