M1 15w-50 actually a "wide-spread" oil?

[Audi Junkie]

Thinking about the reverence there is for M1 15w-50 as the ultimate performance oil. This speculation seems, in part, to be based on the assumption that the 15w cranking test is the lowest it can pass. I know it has exceptional pour-point for a 15w (-49f). So, are we possibly kidding ourselves to think of it as a 15w-50? Is it more like a 10w-50 or even a 5w-50? Maybe Mobil took the track of marketing a "low-spread" oil for performance and 5w-50 Castrol took the "wide-spread" approach for oils whose viscosities are not necessarily much different. Just something to think about. Theory is mostly all I can offer the board.

 

[Jelly]

I think the "ultimate performance oil" title is a very relative one...in comparison to what you can get through mail-order, then no. In comparison to what you can get off the shelf at the local store...without a doubt.

About the 15w thing...yes, it definitely has better cold-temp pumping specs. than the 15w title would indicate.

In comparison, as I understand it, Delvac 1300 15w-40 meets 10w pumping requirements, but sticks with the 15w-40 title because it's known as the "diesel/heavy duty" grade whereas 10w-40 is known as the gas/shear-prone grade.

BTW, I'm a big fan of M1 15w-50. My favorite widely-available PCEO!

[ April 27, 2004, 11:45 PM: Message edited by: Jelly ]

 

[2KBMW]

I was thinking about that too Audi Junkie.
The 15w50 has the same pour point as the
5w/10w 30 oils. What I like is the extra
additive package.

 

[Jelly]

quote:

---

Originally posted by 2KBMW:
I was thinking about that too Audi Junkie.
The 15w50 has the same pour point as the
5w/10w 30 oils. What I like is the extra
additive package.

---

...But their cold pumping specs will not be the same (which really tells you how an oil does in cold temps).

Pour point doesn't mean a great deal...

 

[Eiron]

quote:

---

Originally posted by Audi Junkie:
... Theory is mostly all I can offer the board.

---

Don't kid yourself. We've all got experience that can help someone else. (Hey, who'm I going to call on when my son decides he can't live w/o that '76 Audi Fox he's been eye-ing??

)

 

[Jelly]

quote:

---

Originally posted by Eiron:

quote:

---

Originally posted by Audi Junkie:
... Theory is mostly all I can offer the board.

---

Don't kid yourself. We've all got experience that can help someone else. (Hey, who'm I going to call on when my son decides he can't live w/o that '76 Audi Fox he's been eye-ing??

)

---

Agree!

 

[batterycar]

quote:

---

Originally posted by Jelly:

quote:

---

Originally posted by 2KBMW:
The 15w50 has the same pour point as the
5w/10w 30 oils. What I like is the extra
additive package.

---

...But their cold pumping specs will not be the same

---

(1) Why does 15w have extra additives?

(2) It's been a while, but I think the 15W-50 I used in my old car had pumping down to -20F. That's cold enough for my home.

 

[Audi Junkie]

I would like to see the PP for other synthetics, but my computer chokes on PDFs. At -49f I suspect that it is similar to some 10w or 5w oils. Interesting.

 

[Schmoe]

Totally agree. We ALL have something to offer. There are only a handful of individuals on this board that can get deep down into the actual molecular level, the rest of us know enough to make us dangerous and keep us out of jail

That's is what I like about this board, go over to some other car specific forums and just read the slander. Glad to be here. Now if we could just beam all of ourselves to a bar and discuss all-things-oil in person........

[ April 28, 2004, 12:02 PM: Message edited by: Schmoe ]

 

[Dr. T]

No the Pour Point is USELESS. So what if it exhibits some movement on a vertical surface. It is thick as any other SAE oil at -20 where a 15W needs to meet the spec..

I've used it and it is nothing like the Syntec 5-50. Make no mistake, the M-1 15W-50 is a 15W. The Syntec 5-50 behaves more like a 5W/10W at -25C (temps that I've started the car with it).

 

[Patman]

quote:

---

Originally posted by Dr. T:


I've used it and it is nothing like the Syntec 5-50. Make no mistake, the M-1 15W-50 is a 15W. The Syntec 5-50 behaves more like a 5W/10W at -25C (temps that I've started the car with it).

---

What is the longest interval you've run with the 5w50 Syntec? I'm curious if it's cold starting ability is still as good after 10,000km as it is when new? I just figure that an oil with that large of a spread probably turns into a 10w40 after a few thousand miles (thinning on the hot viscosity and thickening on the cold viscosity)

 

[Dr. T]

I just started re-using it after 3 intervals with the TWS 10-60 and 2 with the BMW (Castrol R?) 0-40 with worse results than the Syntec in the way of consumption and visible sludge content. Seems like valvetrain noise was slightly less with the 0-40, but I need to give the Syntec some more re-cleaning time. Consumption was less with the Syntec than with either of those 2.

I believe the longest I previously had it in was about 4k mi.. I think the used viscosity is somewhat dependant on the relative amounts of fuel dilution as well as oxidation/solubles.