Will GC 0w30 pump faster on cold start than PP5w30

[PT1]

I was wondering if GC will be a better Winter cold start oil for my GM 6.0L?

 

[JAG]

I think if you plotted viscosity vs temperature for the oils you'd see the curves intersect at some cold temp. You'd have to plot them to find that temp. Then decide whether your startups are usually above or below that temp. Note: kinematic viscosity is not linearly related to the cold cranking and cold pumping viscosities which determine the XW designation but Ohio isn't the arctic so I wouldn't worry about that.

 

[Auto-Union]

No, unless you live on the Moon.

 

[Ross]

The GC is thicker until it gets really really cold out, say around -20F or somewhere around there.

 

[shanneba]

Take the specs from both oils and use this calculator to compare the viscosity at your cold start temperature.

Viscosity and Viscosity Index (VI) Calculation

 

[shanneba]

from -40 F to +200 F, Pennzoil Plat. 5w-30 is thinner than GC at all temps.
The VI is almost identical, GC = 167 and Plat = 169.
GC is 12.1 @ 100C and Plat is 10.3

 

[shanneba]

Here are the figures I get from the calculator:

Code:

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Temp Castrol Mobil 1 Mobil 1 Mobil 1 Mobil 1 Mobil 1 Motul Penn

F Syntec 300V Plat

0w-30 0w-40 0w-30 5w-30 10w-30 5w-20 5w-40 5w-30

Vi 167 187 169 169 147 163 176 169

100C 12.2 14.3 11 11.3 10 8.8 13.8 10.3

40C 72 80 63.1 64.8 62 48.3 80.8 57.5



cSt

-40 28357.7 19743.0 22092.0 23154.0 39117.0 17893.0 26299 19703

-30 14234.7 10603.0 11202.0 11734.0 18230.0 8925.0 13610 10004

-20 7591.9 5998.0 6032.0 6314.0 9119.0 4745.0 7447 5396

-10 4278.2 3558.0 3430.0 3588.0 4863.0 2672.0 4920 3074

0 2527.6 2199.0 2044.0 2136.0 2739.0 1581.0 2581.0 1836

10 1560.7 1412.0 1273.0 1329.0 1623.0 979.0 1621.1 1145

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[JAG]

Thank you for the efforts! Interesting results.

 

[addyguy]

Those numbers can't be right - in order for an oil to qualify as a 5W oil, it has to be less than 6600cst@-30, and all of those 5W numbers aren't even close!

 

[paul_e320]

Quote:

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Those numbers can't be right - in order for an oil to qualify as a 5W oil, it has to be less than 6600cst@-30, and all of those 5W numbers aren't even close!

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It's 6600cP at -30C. All those cranking/pumping viscosities at low temps are in cP (Absolute), not cSt (Kinematic) per SAE J300.

This used to confuse me all the time until I finally got it straight.

Regards,
paul....

 

[PT1]

Nice data......thanks!

 

[PT1]

BTW, anyone have the numbers on PP 10w30?

 

[shanneba]

The specs for the PP 10w-30 to use with the calculator:

100C - 10.5
VI 154