Mobil 1 at Pep Boys this Friday, $4 a quart

[William]

The Synthetic Rotella T6 5W40 is not only quieter while the engine is running, but also at startup. And it is cheaper than the Mobil 1, so it is a winner in my book, so for now I will continue using Synthetic Rotella T6 5W40 in my 540!

[Craig in Canada]

[Craig in Canada]

Hi all, sorry to bring this thread out of slumber but I thought I'd add some info I finally tracked down to a thread where we discussed this instead of starting a new one.

I've found the table that I was looking for which documents specifically how "W" grades are rated along with other useful information. You can also see the min/max cSt rating for the hot ratings as well as the minimum HTHS for each grade.



I would like to particularly point out how "W" grades are set. Note that the cP scale is not the same as the cSt viscosity scale. A point I was making at one time was that "W" grades are set by being "at least as thin as X @ Y temperature". What this means is that an oil could handle low temps well enough to be rated a 5W but the manufacturer could CHOOSE to market it as a 10W and unless you dig into detailed specs consumers would never know the difference.

Due to misinformation and ignorance (in the true dictionary definition, not as an insult) "0W" oils scare a lot of consumers in some markets and they will not consider an oil any further if it isn't "10W" because it's "too thin". There are oils out there carrying 5W and 10W ratings which actually perform better. "0W" oils are nothing to be scared about, as long as the rest of the ratings are understood.

A sweeping generalization could be made that "wide spread" (i.e. 0W40 instead of 10W40) oils are more prone to shearing with all other things being equal. The catch is that all other things are almost never equal - especially in current oils compared to even 10 years ago. In reality the 0W40 oil is almost certainly made from more advanced materials than the 10W40 in order to achieve its ratings. In other cases, it could even be the same oil because of how the "W" rating system works.

[JimLev]

as I was stacking all of the M1 0w-40 into the cabinet I was thinking about doing a pour test between the BMW 5w-30 oil that I use in the S60 and the M1, just to see if there was much difference between the two at 20°F and maybe 100°F.

[Craig in Canada]

Careful, Jim. You're going to have to join BITOG and start threads about your "freezer tests" and "hot plate tests". This is the kind of thing some do over there as a hobby...

:-D

It's true that spec sheets only contain viscosity data points at 40C and 100C when it would be more useful if they also included a 0C. Viscosity change with temperature may or may not follow a predictable formula depending on the formulation of the oil. GC, for instance, isn't as thin at midrange temperatures (like 0C) as some of the similar competition (even 5W oils) but by -30C it's reported to remain considerably thinner than all the others (how it gets its 0W rating). So GC is superb at really low temps but there are oils that are thinner at 0C. From my reading, the differences aren't enough to bother me and GC is a great oil with some unique properties.

[JimLev]

than I expected. Like you said the viscosity at different temps changes from their test results.
I took 2 quarts of Mobil 1 0w-40 and 2 guarts of BMW 5w-30 synthetic, heated one of each to 130°F (55°C) and cooled the other two to 20°F (-7°C).
I then poured 8 ounces (.24 liters) of each thru a funnel with an 1/8" (3.2mm) hole and recorded the time it took.

M1 0w-40 @ 130°F = 1 min 41 sec
BMW5w-30 @ 130°F = 1 min 34 sec

M1 0w-40 @ 20°F = 15 min 30 sec
BMW5w-30 @ 20°F = 13 min 15 sec

So M1 0w-40 is thicker at both temps which is OK with me. It should be of interest to many of us with high mileage.

OK, I'm done with oil testing for a long time, this took way longer than I thought it would. Glad my wife wasn't here to see me putting oil in the freezer and in the kitchen sink with boiling hot water.
I'll keep reading your stuff, don't know what half of the abreviations mean, but it looks interesting.

[Scott in Fort Mill]

Mobile one if for Detroit cars.

[PimpSled]

I put some T6 in my 528i and sounds smoother, runs fine. My concern now after reading some posts is the level of zinc and other things that could harm the catalitic converter.

[Craig in Canada]

A couple of things:

1/ T6 is still API rated for gasoline engines. Your owner's manual will probably say API SJ or SL or higher. T6 is API SM, and SM already lowers the allowable amounts of zinc and some other additives from previously allowed levels. Lots of people consider this a "bad thing" and don't progress beyond API SL in order to keep higher levels of zinc (ZDDP, specifically). You would have to be more careful of diesel oils which are NOT dual rated for use in gasoline engines and only carry API ratings like "CJ". Generally the Rotella family is a fleet oil, and they intentionally dual-rate so that companies or counties can use one oil for their entire fleet of cars, trucks and machinery.

2/ If your engine isn't burning oil the zinc isn't getting to your cats in the first place. If you have significant consumption that isn't fixable (like some M54s seem to have) then you might have a point, although as I mentioned above any API gasoline oil could have as much or more zinc than T6 has.

[PimpSled]

and thanks for all the informative posts.

Funny you mention the M54s. My X3 needs to be topped once in a while but maybe if using the T6 stuff that might stop the burning.

[Craig in Canada]

Since I don't have one I haven't researched it heavily, but I've read a lot of posts in different forums from people with M54s and unsolvable oil consumption. We're talking 1qt per 1000miles or more, not a little top up over 5000mi. Some people find it's the CCV or a leak and can fix the problem. Other people have tried everything and the consumption continues.

I've seen a couple of ideas put forward by some experiencing the issue. I've heard that it might actually be valve guides/seals leaking. This allows oil to leak down from under the valve cover into the combustion chamber under either high vacuum (high rpm, off throttle) or when not running (causing puff of smoke on startup). I've also heard that it could be due to the cylinders no longer having iron liners but I also think I've seen this discredited. I think there's conflicting information out there sometimes showing M54s as unlined Alusil and other times as iron jacketed Alusil. The M52 is iron block (no liners necessary) and AFAIK the M52TU is definitely lined.

Depending on what's going on changing your oil may or may not help. I suppose it's worth a try... Sometimes light consumption is actually due to shearing at the ring interface - suddenly your 30 weight is a 20 weight and slips past the oil control rings. Higher RPM, manual trans enthusiasts are more prone to this type of consumption. Other consumption can be due to the rings being coked up and not sealing properly. Then there's CCV, leaks, bad luck...

[PimpSled]

". . . taking 1qt per 1000miles" (PIA)

Me 3-4K miles half a quart to three-quarters oil. Thanks for the feedback.

[M5 LiTE]

And my car has almost 275,000 miles on it - Hmmmm

Will BMW and/or LubroMoly make it last until 500K?

If you use Jiffy Lube oil (which isn't much more than liquid asphalt - bottom of the barrel - literally) not many cars will last very long, but Mobil 1 is fine. No, it's not ester based, but the cracked hydrocarbon based (PAO) is still good stuff.

[Nelson.....]

2000 540i Sport in Houston, TX

[Whorse]

Andreas
Queens NY
BMWCCA# 186796
86 325es (wrecked by careless driver)
87 325 (project for life)
00 540is 6spd (daily driver)