5w-20 Synth vs 0w-20 Synth

[Auto-Union]

I've been purchasing the odd bottle of 0w-20 Mobil 1 to mix down a stash of 0w30 Mobil 1 that I have. I have to reach past the 5w-20 Mobil 1 to get it and it got me wondering. Since 20 weight is pretty thin, it must be easy to make it, as a synthetic, pass a 0w test. Now, I realize many 20 weight synthetics are 5w, but are they and Mobil 1 simply for marketing/meeting mfg spec "designations"? That is to say that oil co.s don't want to miss sales or cause confusion with JQ Public by formulating and labeling their 20 weight synthetics as "0w" when oil caps and manuals call for "5w"? Heck, we don't see 10w-20s! Us guys here on BitOG understand that 0w-20 for synthetic and 5w-20 for dino/blends is a good way to go, but is there more to it than formulating....marketing perhaps???

 

[rpn453]

It's certainly possible!

 

[farrarfan1]

But does it matter?

 

[Blue99]

quote:

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Since 20 weight is pretty thin, it must be easy to make it, as a synth, pass a 0w test.

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Yes, but keep in mind that the high temp viscosity and Noack volatility requirements must also be met.

As we have learned on Bitog, PAO formulations are typically blends of 3 or more PAO base oils - example 4 cSt, 6 cSt, and 10 cSt - at a ratio to meet both the cold & hot viscosity targets.

What puts a blender in a "box" is that as more 4 cSt PAO is added to meet the 6200 cP @ -35 cold crank spec, the hot end performance slips, as the 4 cSt base oil tends to be right at 15% Noack and drops the blend below 8.5 cSt.

So a finished PAO motor oil will perform better on the 100 hrs @ 300F degrees Sequence IIIG test, if it has more of the heavier weight base oils and just enough of the lite base oils to meet the xW grade.

 

[Auto-Union]

Thanks, Blue. So, it is somewhat easier for a blender to make a 5w oil? I figured the two specs were within a hair of one another. It matters in the sense of understanding why 2 different 20 weight synths are taking up shelf space and what the differences are for the consumer and BitOGer.

 

[Blue99]

Auto-Union, it looks to me that Mobil 1 0W-20 is being marketed as a gasoline/electric hybrid motor oil & that's the reason it is back on the market.

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_0W-20.aspx

Yes, the two 20 weight options tend to be redundant, as I think that for most users in the lower 48 states, 5W-20 meets the majority of cold temp starting requirements.