0W is for colder?

[21Rouge]

On the labels:

M1 5W-30: "Pours at -45C"

German Castrol 0W-30: "..allows for unaided engine starts down to -40C."

Esso XD-3 0W-30: "...start ability and pump ability to -40C."

Just wondering why the colder number for the 5W over the 0W?

 

[bruce381]

"Pours at -45C"
Please note the words "pours" and "start". An oil that pours at -45 will NOT pump at -40. The pour point test not as accurate or real world enough for a good evaluation of performance in
a overhead cam engine. But it will give a sexier lower number just dose not mean much.
bruce

 

[21Rouge]

quote:

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Originally posted by bruce381:
But it will give a sexier lower number
bruce

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Motor oil and sex. Bruce you are starting to sound like pscholte

.

And as I recall M1's OW-30 pour point is something like -54 C!

Would all 0W-30s, for example, necesarily have the same pour temp and then also identical pump temp?

 

[TooSlick]

One number is the "Borderline Pumping Temp" or BPT and ones' the Pour Point, or PP.

The BPT is defined as the temp at which the viscosity of the oil increases to 60,000 Cp - regardless of its' original SAE grade.

The PP is 5F above the temp at which the oil won't flow at all, in a tipped beaker of fluid. As Bruce alluded to, it's good for advertising, but is below the useful lower temp limit for the fluid.

Tooslick
Dixie Synthetics

 

[jorton]

"0w is for colder?" No and yes. 0w is synthetic and synthetic is for colder in the great white north. You would be ok with 0w or 5w.

 

[Paranoil]

The pour point of Castrol SLX (aka GC) is -54C (ISO 3016 / ASTM D97)

 

[haley10]

Heyjay used to have a lot of good comments on this subject. He actually had to start and go in these temps. Pour point is not too meaningful. Looking at CCS and MRV data is a better tool for real world performance.

Compare MRV data especially and you will see there is a big difference in 0W oils if you need to start in the extremes.

In fact a 5W might cold crank better than a 0W if your not at the extreme of the range, i.e. M1 5W-30 vs. GC 0W-30 at say -5°F.

If it's really -40°C outside, I haven't seen any better #'s than Mobil 1 0W-30.

[ August 01, 2005, 10:58 AM: Message edited by: haley10 ]

 

[21Rouge]

quote:

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Originally posted by haley10:
In fact a 5W might cold crank better than a 0W if your not at the extreme of the range, i.e. M1 5W-30 vs. GC 0W-30 at say -5°F.

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I never even considered such a possibility. Why would that be? I just thought at the in common temperatures at which 5W-30 and 0W-30 are rated for they would perform identically.

 

[haley10]

quote:

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Originally posted by Boxgrover:

quote:

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Originally posted by haley10:
In fact a 5W might cold crank better than a 0W if your not at the extreme of the range, i.e. M1 5W-30 vs. GC 0W-30 at say -5°F.

---

I never even considered such a possibility. Why would that be? I just thought at the in common temperatures at which 5W-30 and 0W-30 are rated for they would perform identically.

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Hopefully 427ZO6 will grace us with his chart. Actually Amsoil 10W-30 ATM is a decent cold performer despite the 10W rating. Like Heyjay implied there is a lot more than the xW rating.

He was somewhere in Canada and a search might turn up some old posts. Anyway, I only look at MRV and CCS #'s . The xW numbers are only relevant for meeting the spec. at the temp. required they be measured at.

In Tennessee, I will never see my GC 0W-30 flow better or be thinner than Mobil 1 5W-30. It's not linear and I wish we could show some graphs.

 

[Triple_Se7en]

Quote:
I only look at MRV and CCS
==============================================

Both of these are not even listed in the Oil Acronyms chart.
What are both?
What are good numbers for each?

 

[Blue99]

Looking thru my product data sheet file, a -36C pour point is common for many 5W-30 dino's. This pour point is just -6C degrees away from the 5W cold crank rating temp of -30C.

What has always been a bit curious to me, is the Trop Artic 5W-30 CCV rating is 5300 cP at -30C, and the listed pour point is -31C.

So it meets the cold crank spec at -30C and 1 degree colder, it bumps into the pour point!

But, as TooSlick noted, pour point is still 5-6 degrees away from the no flow point.

The Trop Artic 5W-20, 5W-30 & 10W-30 all share the same -31C/-24F pour point. Probably a very good indicator of the effectiveness of pour point depressants used with Grp III base oils!

 

[haley10]

quote:

---

Originally posted by Triple_Se7en:
Quote:
I only look at MRV and CCS
==============================================

Both of these are not even listed in the Oil Acronyms chart.
What are both?
What are good numbers for each?

---

I'm getting in over my head here and need help. CCS is Cold Crank Simulator and I think MRV is Mini-Rotary Viscometer. I'm not an expert and can only go by comparative values.

My knowledge is limited, so please excuse. I don't pay a lot of attention to this because I never have to crank much below 0°F.

It would be nice if bitog had a standard reference for this.

 

[21Rouge]

quote:

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Originally posted by bruce381:
Please note the words "pours" and "start". An oil that pours at -45 will NOT pump at -40. The pour point test not as accurate or real world enough for a good evaluation of performance in...

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And speaking of real world performance in the winter: does wind chill temp have any effect on engine oil?

 

[burnout]

I wouldn't think it does, because the wind never directly touches the oil.

 

[21Rouge]

quote:

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Originally posted by burnout:
I wouldn't think it does, because the wind never directly touches the oil.

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I guess what I mean is this: Is a 0W more suitable than say a 5W for a temp which is -15 degree C without windchill but say -35 C *with* the windchill factored in?

I thought I recall that windchill is a rating which affects only warm blooded creature but from experience my car seems much more balky sitting outside when there is excessive cold wind.

 

[XS650]

Wind will cause it to cool down a bit faster (if it didn't, they wouldn't waste money putting fans behind radiators

) , but it still won't get any colder than the air temperature.