OK... it just looked like the out of date spec book (still does). Doesn't matter, just curious if you had one newer than the date I posted.

 

I'll have to admit that I put myself in the category of "knowing enough to know that I don't know a final answer" on what oil is the best choice. That said here is one of the more interesting write-ups I have read on the subject: Motor Oils - Fuel Economy vs. Wear


an excerpt:
"To determine if SAE 5W-20 oils provide the same level ofprotection as SAE 5W-30 oils, Dagenham Motors in England, one of the largestFord dealers in Europe, was consulted. SAE 5W-30 is required for warrantypurposes in England, and SAE 5W-20 is not even available. If SAE 5W-20 werebetter for both fuel economy and wear, why would Ford not recommend it for itssame engines in Europe? "

 

WTF? We can buy 5W20 oil, no trouble at all.

(It's not spec'd for my car, but is easy to buy.)

 

That article is from 2003. 5W-20 used to be hard to find in the U.S. at one time as well.

Also, the trend towards thinner oil in modern engines hasn't resulted in the engines wearing out prematurely in the cars speced for that thinner oil. Modern oil formulations with modern anti-wear additives (trimer moly w/ZDDP, etc.) appear to be working as designed.

 

Early on the 5W-20 was hard to find .. as was the 0W-20 and 40 ... I used to have to order in the 0W-40 at my local Pep Boys when they had the M1 deals for my 2001 Porsche. Obviously, the dealer had it.

The 5- 30 was the most fuel efficient oil back when these were designed -- so it stands to reason the cars would be designed to run that oil. The EPA did and does require the testing oil to be the preferred oil. Can't have a manufacturer designing an engine for one oil -- testing for EPA on a thinner oil not suitable for the engine to pass a test .. and place another oil in the manual.

Maybe VW would.

 

Ok, I just got sucked into the oil black hole discussion for a few minutes and have a question. The reason I ask it here is because there are a couple of people who have posted in this thread that I have come to respect for their knowledge and experience, and even direct advice in the past...so I want THEM to see my question.

I am headed out to buy oil for the 2003 XJR I am picking up tomorrow. I have generally used Mobil 1 5w30 full synthetic in my XJ8, and my wife's XJ8. I see that it meets neither the ACEA 3 OR the Ford WSS-M2c913-b specification. Upon recommendation on here recently I switched to Mobil 1 0w-40 fully synthetic in one of my XJ8s. I see that it DOES meet the ACEA 3 but NOT the Ford WSS-M2c913-b specification.

I found Castrol Magnatec which meets Ford WSS-M2c913-b but NOT ACEA 3.

Should I really care about meeting both requirements? Is there an oil that meets both? If I'm picking one specification to meet, which one is more important?

By the way, I could put either oil in and sleep well at night, but I do find it interesting to better understand what I'm putting in the car.

 

You're quite wise. Your car will sleep well too with either of the oils, or any of the choices you might make using the factory guidelines. There's really not much evidence to show that it makes any difference.

 

Redline claims to meet both, but it's $50 a gallon! I think I'll stick with the Mobil 1 0w-40 for half the price.

 

I don't think it's possible for one oil to meet both the Ford WSS-M2c913-b specs and ACEA A3 specs. According to this (Ford Oil Specifications - oilspecifications.org), the WSS-M2c913-b spec calls for a passing oil to be ACEA A1 (HTHS measuring less than 3.5) while ACEA A3 calls for an HTHS measurement of 3.5 or greater.

Redline 5W-30 has a 3.7 HTHS, so it's an ACEA A3 oil, but is too thick HTHS-wise to meet the Ford WSS-M2c913-b spec.

 

Since the ACEA A3 is specifically mentioned for the supercharged car, and that is what I am buying it for, then I will give that spec priority. That still leads me to the Mobile 1 0w40 European formula.

Just left Walmart with two 5 quart jugs of it...decision made.

 

When was the last time we had an engine failure on this forum due to poor lubrication/oil ???
oil is a non issue

 

Yep.

 

That's one of the usual three top candidates in the class.

I have never used it because there are other oils in the
class that seem to edge it out.

No reason to dump it out though

For the curious, I am currently running Castrol European 0W40
meeting ACEA A3/B4, as well as a slew of Mercedes, BMW, Porsche
and VW specific specs. Look for "Made in Belgium" on the back
to ensure that it is the right one. It is also API SN.

This was picked to replace the previous Castrol 5W50 which was
a tad sluggish at -30F after overnight soaks.

At 6,000 miles, it came out completely black. This is not in and
of itself bad as having it come out with the oil is better than
leaving it in the engine. Running it to 10,000 miles would
really be stretching things. It was already impossible to
see any light through a clear plastic water bottle using
a LED flashlight. Not even a hint of light came through
the oil.

Having done the above, I am leaning to going back to the
Rotella T6 0W40 on a permanent basis. It is suspected to
have HTHS in the region of 4.

The page linked below is a very interesting read. It is focused
on the history of oil recommendations for the Jeep 6 cylinder
manufactured from 1986 through 2006. See how they move
in reponse to regulatory influence, even though the engine
itself has not changed. Also see how Jeep changed the
recommendation for North America to thinner oils while
at the same time keeping ROW markets at the same historical
ranges while moving up to requiring ACEA A3.

The final conclusion of the first post, which will take an hour
to read, is Shell Rotella T6 0W40. The reasoning is pretty
solid. I would use it in any Jaguar engine prior to the
5.0L engines and the same period V6.

Rotella: The world's first ever combined hair oil, foot ointment, and salad dressing - Jeep Cherokee Forum

++

 

+1 for the Rotella. After doing some research on my last forum, that link repeatedly came up. The Rotella was the recommended oil by most on the forum, for good reason. Because of that, I use it in my current daily driver (a 20,000lb turbo diesel military surplus truck,) and I will use it in my Jag when I get it

I used to be a hardcore Mobil 1 guy, but now I'm going to stick with Rotella

 

I take it 0.1 MPG doesn't matter to you then?

 

I've always been an advocate of synthetics (took my Expedition to 693k) and I use Mobil 1 (work vehicles) or Royal Purple (in the Jag and Vette). I try to stay with Royal Purple, but its availability locally isn't the best.
I have delved into the syn-blends, but only for my work vehicles when oil skyrocketed and found Fords syn-blend to be the best for me. My Expedition was very easy to tell what oil was working in it, simply by the mileage it got (or didn't, half full...half empty view) and I keep tabs on rpm's vs speed. Plus I run my synthetics out to 12k-15k between changes...except the Jag, that SC kind of pushes some around the rings with my heavy foot. I tend to add a quart about every 4k or so.
Overall I want to thank Plums for an interesting article and the responses to it. Y'all will want to keep in mind that a good oil will only perform as well as the filter that its working with. Be sure to get the smallest micron specific filter for best results.
I may put in a oil bypass on my work vehicle, mainly because of even less oil changes, but also because of its micron per fluid ounce reduction and lessening of wear on components. For example, AMSOIL's filters down to 1/10th of a micron.

 

What does that tell you?

 

lol.. Not really Though it does get surprisingly good gas mileage, all things considered.. Usually 8-10mpg. Might get 12 if you're lucky. That's why I picked an A2, because it has the smaller Cummins 8.3L turbo. The A1 and older trucks had a naturally aspirated 14L Cummins, which made the same power (though the 8.3 actually makes more torque.) But the 14L Cummins trucks only get 3-4mpg, which is not so great for a daily driver

I'm actually selling it now, as part of my "Jag funding project." I also need to pay off some medical bills for a lower back surgery, etc. I already sold my other daily driver, a '66 Ford Fairlane, to help raise some cash.

 

I look for best fuel mileage vs rpm range, on the Expedition 2100-2150 was the best for it, roughly 74-76 mph. On the Jag it doesn't matter and I don't care....get out of my way...lol

 

I've had the bypass hardware sitting around for
a couple of years. There aren't many convenient
places to plumb it.

One for the engine, one for the transmission.

The transmission appears to be easier, although
finding a place for the remote mounts is still
problematic.