15w40 in 6.7

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Aug 9, 2012 | 05:39 AM

#16

macguy

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Joined: Feb 2012

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Quote:

Originally Posted by TRENT310

I went for 15W40 this time due to product availability... last time I used 5W40 so I will compare the differences, if any. Both types are synthetic.

I know people can talk about oil for hours on end... how the '40' weight is actually thickened by additives and when the additives wear out the oil goes back to the cold weight since it can't deteriorate any more than what it originally started off as. But if you do your oil changes it should never get to the point where those additives wear out anyway.

Which 15w40 synthetic are you using? Doing some reading, 15w40 synthetic both from Mobil and amsoil can be used down to 0f and still protect.

Aug 9, 2012 | 07:04 AM

#17

RM2012F350

Senior User

Joined: May 2012

Posts: 137

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From: Pleasants Co. WV

Quote:

Originally Posted by macguy

I'm not a fan of changing between dino & synthetic. I agree synthetic is superior, and may European cars use it standard from factory. But changing between the two based on ambient temp is, just doesn't seem like its good for the engine and its seals.

Oh that is way! Old school thinking...

Aug 9, 2012 | 07:02 PM

#18

TRENT310

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Joined: Jan 2010

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From: Whitecourt AB, Canada

Quote:

Originally Posted by macguy

Which 15w40 synthetic are you using? Doing some reading, 15w40 synthetic both from Mobil and amsoil can be used down to 0f and still protect.

Ford Truck Enthusiasts Forums - View Single Post - Well........it happened.

Aug 9, 2012 | 08:19 PM

#19

doublenot7

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Joined: Oct 2011

Posts: 400

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From: Gulf Coast, Texas

I'm on the Texas Gulf Coast, been running 15w40 (which is what the dealers seem to run here). Just switched to Mobil synthetic 5w40 yesterday (with the assistance of my 4 year old helper).