Need some help with GC ?s

[Stainless]

#1 What is the CST of german castrol 0w30 at 40C and lower temperatures? I have been looking online, and I can NOT find an answer to this. The PDS lists the CST at 100C at 12.1. It also lists the cold temperature cranking viscosity as 6200 @ -35. But, I can't find the cst at 40C.

#2 Would GC be thicker or thinner than Mobil 1 5w30 at temps of 0-70F? That's my major concern.

#3 Is GC SM rated? I checked the PDS, and it is not, but the PDS was from 8/15/05, so I do not know.

#4 My mom has a 2005 Jeep Grand Cherokee, with the 4.7 V8. She has been runing Mobil 1 5w30. Just the regular Mobil 1, not the Mobil 1 Truck and SUV or the EP. I noticed that this SUV runs RIGHT AT the thermostat temp constantly. It NEVER goes below it. NO matter how cold it gets, the coolant temp is always the same. Since my reading, that 5w30 shears down to a 20 weight, would it be better to run the thicker 0w30 GC since the SUV is always warm?

Yes, I know a used oil analysis would answer a lot, but this isn't my car, & I don't have the time to take care of everything for my mom. Just an educated guess would be appreciated.

thank you.

 

[Quickbeam]

Can't help with all but the batch I bought last week was SL and was recently date coded.

You don't have time to take care of your Mom?

 

[AndyH]

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#2 Would GC be thicker or thinner than Mobil 1 5w30 at temps of 0-70F? That's my major concern.

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I don't have any data to support this (although I seem to recall someone posted this data previously), but I believe GC would be thicker than Mobil 1 5w30 from 0°F - 70°F.

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#3 Is GC SM rated? I checked the PDS, and it is not, but the PDS was from 8/15/05, so I do not know.

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No, GC is SL rated.

 

[glxpassat]

CST @ 40 = 68 if I remember right.

Sounds like the thermostat is doing it's job perfectly! For the same price, I would use the GC.

 

[RD400]

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I noticed that this SUV runs RIGHT AT the thermostat temp constantly. It NEVER goes below it. NO matter how cold it gets, the coolant temp is always the same.

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I don't know about this vehicle, but many newer ones now have a digital temp gauge, even though it shows a needle on a scale. So if it's operating within a certain temp range, the needle won't move like an analog meter would. If it's steady, it does sound like the thermostat is working properly.

 

[B00SS]

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I don't know about this vehicle, but many newer ones now have a digital temp gauge, even though it shows a needle on a scale. So if it's operating within a certain temp range, the needle won't move like an analog meter would. If it's steady, it does sound like the thermostat is working properly.

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This is true. My Camaro has one of these guages. It shows just shy of 210 after warm up. No matter how hot or cold. Now if it raises above some temperature (unknown to me) then it will actually show higher. But within a range it shows shy of 210. I have never had it show otherwise after warming up.