Oil weight

[WY-Dave]

In a 5W-30 for example, the number before the W describes the viscosity of the oil at low temperatures.
The lower the number, the thinner the oil and the better the oil's cold temperature/ cold start performance.
The number after the W describes how thick the oil is at the engine's normal operating temperature.

 

[jejb]

In a 5W-30 for example, the number before the W describes the viscosity of the oil at low temperatures.
The lower the number, the thinner the oil and the better the oil's cold temperature/ cold start performance.
The number after the W describes how thick the oil is at the engine's normal operating temperature.

Correct. But there's also the syn vs non-syn cold pour point discussion. For the subject truck, the 10w-30 recommended oil does not have to be syn. The 5w-40 does. So being both lighter at 5w and being syn makes it a better choice for cold weather startups.

 

[Dusty]

Actually, Pour-point has nothing to do with the winter rating. There are no minimum/maximum pour-point specifications set by the SAE and there is no Pour-point sequence test required by the API. Depending on the specific oil's recipe of base stock and additives used by a particular supplier, it's possible for a 5W to have a lower pour point than a 0W. Example: Valvoline Advanced Synthetic 0W-20 has a pour point of -39C while Pennzoil Platinum 5W-20 is -48C and Mobil1 5W-20 is -51C.

Pour-point cannot be presumptively used to rate flow. An oils winter rating is now determined by how it performs in the Cold Cranking Simulator (CCS) and the Mini-Rotary Viscometer (MRV) tests, both of which have maximum viscosity limits at various temperatures. For example, 0W oils cannot exceed 6200 centipoise (cP) at -35C and 5W oils cannot exceed 6600 cP at -30C in order to pass the CCS test.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 100717 miles.

 

[HEMIMANN]

Yeah, but good luck finding CCS specs anymore. Or HTHS vis or NOACK volatility.

Most lube blenders have pulled the most useful specs and turned info over to MBA wordsmiths with flowery adjectives meaning nothing.

 

[Dusty]

Yeah, but good luck finding CCS specs anymore. Or HTHS vis or NOACK volatility.

Most lube blenders have pulled the most useful specs and turned info over to MBA wordsmiths with flowery adjectives meaning nothing.

You weren't kidding. I just spent fifteen minutes trying to find just one:

https://www.pennzoil.com/en_us/pennzoil-platinum/_jcr_content/par/productDetails.stream/1460058453075/170f0cbfa6bad2c5c32bb82fd7cef60c84eee098/Pennzoil-Platinum-SAE-5W-30-Full-Synthetic-Motor-Oil.pdf

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 100808 miles.

 

[jejb]

Actually, Pour-point has nothing to do with the winter rating.

I didn't say they did. I only trying to point out that syn oils generally have lower pour points than conventional oils, given the same W rating.

 

[Dusty]

I didn't say they did. I only trying to point out that syn oils generally have lower pour points than conventional oils, given the same W rating.

Yes, I understood that. I just commented to clarify for others who may be confused on the subject.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 100808 miles.

 

[Willie Mosher]

The Manuel book say to used 0w40 an with an Ms number
Ram / Fca or other have spent thousands $ € ¥ to figure out best Oil
To keep from buying Engines them self,

But if you think can go autozone
Talk to 20 old kid make $15 hours
An out do FCA GM Ford or other,
It your money.

 

[Redfisher1974]

The Manuel book say to used 0w40 an with an Ms number
Ram / Fca or other have spent thousands $ € ¥ to figure out best Oil
To keep from buying Engines them self,

But if you think can go autozone
Talk to 20 old kid make $15 hours
An out do FCA GM Ford or other,
It your money.

I think I’m having a stroke…