Mobil 1 5W-30 -vs- 0W40

[dragboat]

Jay,

Thats some good info you posted. Any guess what the Mobil 1 Supersyn 15/50 would actually qualify for on the low end ?

Thanks in advance

 

[Jay]

quote:

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Originally posted by dragboat:
Jay,

Thats some good info you posted. Any guess what the Mobil 1 Supersyn 15/50 would actually qualify for on the low end ?

Thanks in advance

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M1 15w-50's cold pumping specs are so good that it could probably make it to 5w, but it is limited to 15w on it's cold cranking ability. That's why the SAE requires both tests. M1's 5w-30 comes closest to qualifying for the next lower w rating.

 

[Jay]

Ken had posted this great link that has all the SAE J300 motor oil viscosity requirements. It took me awhile to find it:

http://www.chevron.com/prodserv/NewOronite/library/li_viscosity_motoroil.htm

 

[dbrowne1]

quote:

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Originally posted by TooSlick:
Well, I'd buck the "collective wisdom" on this one and run the Mobil 1, 0w-30 or 5w-30. I just think the 0w-40 is a bit thick for a brand new, high revving engine, especially in the winter. Why folks think they know more than the engineers that actually designed this engine is beyond me.

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What if the manufacturer calls for an XW-40? I was getting very good analysis from Mobil 1 5W-30, but nonetheless switched to 0W-40 when if became more widely available. My owner's manual recommends a 5W-40.

 

[VaderSS]

I say run what the manual says with 1 step up being perfectly acceptable, maybe even preferable. If there are warranty issues, and you can't bring yourself to lie about it, then you should run exactly what the manual indicates.