Mixing brands with same weight

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I have been using Shell Rotella T6 5W/40 for my 2014 F250 6.7L diesel but can't find any right now.

Can I use any other brand of diesel oil with the same weight to top off my oil in my truck? I need probably a quart.

I'm thinking about using Mobil Delvac 1 5W/40
 
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Here are a few prior threads on that subject, there are more but I got tired of copying and pasting:

 
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I often mix anything and everything I can find, especially in old beaters where people don't want to spend money.

That said my Mother had a Suzuki Jimny, she had it for 8 years buying it brand new in 2013 and I used to change the oil every 2 years in it. Somtimes I'd fill it with 4 or 5 different brands, specifications and viscosities. Never had an issue.
 
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Why would you ask. I wonder why we think this. Not being mean but this is a common question and I wonder why we think it could be a problem
People question whether the base stocks or additive packages of different oils are miscible. It's not a dumb question, even if the answer is yes and has been said hundreds of times. The dumb part of this is not the question itself, but not using the search button.
 

tradosaurus

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People question whether the base stocks or additive packages of different oils are miscible. It's not a dumb question, even if the answer is yes and has been said hundreds of times. The dumb part of this is not the question itself, but not using the search button.

Or maybe the "Similar threads" help function below the message you are typing didn't answer my question which was specific for diesel oils.

Or maybe the dumb part of your post was spending the time and energy to type something but not answering my question?

Thanks to the others that actually gave me an answer.
 
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If you’re going with Delvac 1, you’ll have the choice of ESP or Turbo Diesel Truck. I use the TDT for my small engines, and once break-in is complete, on the rebuilt 460 in my ‘77 F250 Supercab. Since yours is new-ish, check the certifications to make sure it’s approved. No IC anything I own is newer than 2004. Oh… or you could buy Rotella T6 oil from an opportunist like the one near me for $175/2.5 gal. 😳
 

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People question whether the base stocks or additive packages of different oils are miscible. It's not a dumb question, even if the answer is yes and has been said hundreds of times. The dumb part of this is not the question itself, but not using the search button.
There are only a hand full of additive producers and an handful of oil producers and the oils are designed to be compatible. I would say why don't you buy add oil when buying the oil to do the oil change saving a trip to the store.
 
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Or maybe the "Similar threads" help function below the message you are typing didn't answer my question which was specific for diesel oils.
That isn't the deciding factor. Any oil which passes ASTM D6922 has proven that it is miscible with any other oil that also passes the test. This test is part of all API licensed oils so if that's what you're mixing then you have assurance that there will be no resulting harm from the mixture.

But on the other hand this only addresses miscibility and that is all that's guaranteed. There is no guarantee the mixture will still meet the requirements for any license, specification nor approval any of the mixed oils may have carried on their own. Nor is there any guarantee the oil will still meet the performance requirements for the winter ratings. It only means the mixture will not cause harm.
 

dnewton3

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Generally, mixing any brand/grade/base of API licensed lubes (all within the same category) is perfectly fine, if the lubes are mass-market products.

At times, you may be at risk if you are using boutique lubes which have vey specific formulations and then try some other speciality lube in the middle of that OCI. Dave Ward from HPL can talk to this subject deeper, for example. They use some very, very specific additives that, if over or under dosed, can lead to issues. Some additives they use are very sensitive to the right percentage concentration in solution; the anti-foam agents for example. So if you add some other lube or lube-additve to their products, you may risk upsetting the delicate balance of the add-pack. But this is the exception to the rule, and does not apply to most off-the-shelf retail products.

Using broad-based market products are very unlikely to having their chemistry upset, because the add-packs in those products are similar and compatible per the API license category. Don't do things like use a GL-5 gear oil where you need an HDEO, or vice versa, but using one HDEO where another HDEO is already in use is fairly safe.
 

Astro14

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Your engine holds, what, 12 quarts?

I would use a quart of the same brand, in a slightly different viscosity (say 10W30, or 15W40).

You won’t be changing the viscosity by much, and the additive chemistry will more likely be the same.
 
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Why would you ask. I wonder why we think this. Not being mean but this is a common question and I wonder why we think it could be a problem
I've often read that when repacking wheel bearings you should remove all the old unknown grease from the hub so you don't mix that with the new grease. Not sure why but grease is basically thick oil so why wouldn't it apply to oil as well?
 
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On one hand you have the people that think it's a bad idea but have no verifiable proof of such . Then you have those of us that have done it many times and have had no issues . That seems to happen a lot around here . ;)
 
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On one hand you have the people that think it's a bad idea but have no verifiable proof of such . Then you have those of us that have done it many times and have had no issues . That seems to happen a lot around here . ;)
I looked back through this thread, who thinks it's a bad idea?
 
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