Mixing engine oils?
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Tuned
Joined: Aug 2017
Posts: 299
Likes: 31
From: SW Utah
Mixing engine oils?
Wondering if it’s worth it or even safe to mix two different engine oils I have for my next oil change? I have about 7 quarts of CK-4 Rotella T6 5w/40 and about an equal amount of older CJ-4 Delo LE 5w/40. Both are full synthetic. I’m sure I’m breaking some rule of the oil gods! LoL. Would the different additive packages work against each other?
Postmaster
Joined: Jan 2005
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From: BC Canada
As long as they are both the the higher, approved API CK-4 rating for the power stroke it’s not an issue. The Delo maybe CJ-4 only. This is compatible with the EGR systems of the 6.0 and 6.4 but not the 6.7 I believe.
Junior User
Joined: Feb 2019
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Wondering if it’s worth it or even safe to mix two different engine oils I have for my next oil change? I have about 7 quarts of CK-4 Rotella T6 5w/40 and about an equal amount of older CJ-4 Delo LE 5w/40. Both are full synthetic. I’m sure I’m breaking some rule of the oil gods! LoL. Would the different additive packages work against each other?
https://www.ford-trucks.com/forums/1...for-6-7-a.html
Elder User
Joined: Jun 2017
Posts: 685
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I'm not a believer in mixing oils, but as long as they are approved by Ford for use in the motor you should be good to go. I wouldn't make a habit of it though. Now if the oils were conventional and synthetic I would not mix them unless it was an emergency.
Senior User
Joined: Dec 2018
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Same here +1
Posting Guru
Joined: Feb 2018
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You can mix synthetic and conventional. It's sold over the counter as a blend. Motorcraft even sells their label blend. You can mix oils and as long as they all meet the minimum specifications for your engine. There used to be a smokey, general caution about mixing oils from various manufacturers with a belief the additive packages could conflict, but that was never a proven outcome.
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Senior User
Joined: Aug 2016
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You can mix synthetic and conventional. It's sold over the counter as a blend. Motorcraft even sells their label blend. You can mix oils and as long as they all meet the minimum specifications for your engine. There used to be a smokey, general caution about mixing oils from various manufacturers with a belief the additive packages could conflict, but that was never a proven outcome.
Sam
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Hotshot
Joined: Oct 2015
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From: Wyoming
Mixing the oils listed should be fine. As far as CJ vs CK goes, CJ is the older spec and it's still OK to use. There is a very specific list of CK oils that Ford is OK with. You won't find any CJ oils on that list because it specifically addresses the problem that Ford had with the CK specification.
Postmaster
Joined: Jan 2019
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I’m pretty sure I read somewhere or watched a ford video that states you are not supposed to use CJ4 oil in these super duties. CK4 is what you are supposed to use according to the owners manual.
EDIT: I had that backwards. Ford does not recommend CK4 oils. CJ4 is what is recommended.
EDIT: I had that backwards. Ford does not recommend CK4 oils. CJ4 is what is recommended.
Hotshot
Joined: Oct 2015
Posts: 19,685
Likes: 12,806
From: Wyoming
I’m pretty sure I read somewhere or watched a ford video that states you are not supposed to use CJ4 oil in these super duties. CK4 is what you are supposed to use according to the owners manual.
EDIT: I had that backwards. Ford does not recommend CK4 oils. CJ4 is what is recommended.
EDIT: I had that backwards. Ford does not recommend CK4 oils. CJ4 is what is recommended.
Thread Starter
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Tuned
Joined: Aug 2017
Posts: 299
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From: SW Utah
LMFAO!!!!!!
