Mix Oil Brands for Oil Change?

[wemay]

Originally Posted By: Clevy
Originally Posted By: BHopkins
Originally Posted By: Clevy
Originally Posted By: camrydriver111
What happens if I mix Mobil 1 and Castrol?

I know a lot of people say mixing is safe, but have you tried mixing those two specifically?




I have. In fact I've mixed every known brand and grade at one point or another. Engines are spotless. No issues. Ever


Clevy,

Based upon your comment, I feel better about the idea of adding a quart of PP to top off the RP. Thanks.


No problem.

To be honest it's rare that I don't mix brands only because I'm usually finishing one jug and cracking a new one,so if I think back I don't remember the last time I didn't mix brands.


You don't get more real world than this, and Clevy isnt the only one I know doing it. New, old, forced induction, normally aspirated... the full spectrum of vehicles.

 

[deven]

Originally Posted By: BHopkins
Originally Posted By: A_Harman
Originally Posted By: BHopkins
Originally Posted By: sicko
Check out: http://www.pqiamerica.com/March2013PCMO/Marchsyntheticsallfinal.html

Looks like it'd mix really well with NAPA Synthetic or Valvoline SynPower. I'd say wait until NAPA has their synthetic on sale for $3.79 a quart (they have it every couple of months), and pick up a quart.


Thanks. That's pretty helpful. It looks like Valvoline Syn Power is also very similar in makeup to RP.



I think deven's head just exploded!


Yea, I actually thought of him as I typed that. No offense intended, I was just expressing what I observed. However, your comment made me laugh out loud.

Hey guys. My head is all fixed and I feel much better.

 

[wemay]

LOL... good to know Deven.

 

[fdcg27]

...and the point of Shannow's post flies over many oblivious heads.

 

[Oil Changer]

Yea, but those oil recommendation threads draw thousands of hits!

Originally Posted By: fdcg27
...and the point of Shannow's post flies over many oblivious heads.

 

[fdcg27]

I guess it just bothers me a bit that the OP asked a serious question and got many answers, one from a very thoughtful and bright member who has debunked the common perception of the API compatability standard in a number of threads and who has also provided links to actual lab results indicating that the interaction between VIIs could result in a much thicker oil at start-up temperatures than any casual blender might anticipate.
Instead of having most of us sit back and realize that we hadn't considered either, we still have a bunch of members telling the OP to mix away with no concerns.
Kind of makes you wonder whether folks bother to read threads before they post in them, or whether they can read critically at all.
The standard applied by many seems to be that if the engine hasn't blown up, then whatever they've been doing must be fine.

 

[OVERKILL]

Originally Posted By: fdcg27
I guess it just bothers me a bit that the OP asked a serious question and got many answers, one from a very thoughtful and bright member who has debunked the common perception of the API compatability standard in a number of threads and who has also provided links to actual lab results indicating that the interaction between VIIs could result in a much thicker oil at start-up temperatures than any casual blender might anticipate.
Instead of having most of us sit back and realize that we hadn't considered either, we still have a bunch of members telling the OP to mix away with no concerns.
Kind of makes you wonder whether folks bother to read threads before they post in them, or whether they can read critically at all.
The standard applied by many seems to be that if the engine hasn't blown up, then whatever they've been doing must be fine.


Amen.

Shannow's posts on this subject have been extensive and detailed. Yet every time it is brought up, instead of the potential caveats associated with such an endeavour being discussed in earnest and the fact that it SHOULD be OK "but...." being the theme of the subject we have folks completely dismissing the technical aspect of the process and instead advocating that "home chemist: the oil game" brings with it "no issues", tossing out anecdotes as proof of their mantra, seemingly oblivious to what Shannow posts on the subject.

And this happens EVERY TIME

 

[Oil Changer]

Originally Posted By: fdcg27
...or whether they can read critically at all.
The standard applied by many seems to be that if the engine hasn't blown up, then whatever they've been doing must be fine.


That's it in a nutshell. Some have read the easy-to-read SN standard and think, "Oh, mixing is great!" even though they don't understand what the standard means [Insert lack of critical thinking here]. Others will eagerly post that they have mixed in the past and their engine didn't blow so, "Mixing is great!" even though they are clueless as to what is actually happening in the crankcase. The rest will gloss over Shannow's technical posts (which brought some of us here to begin with), their minds drift, then go read a Royal Purple train wreck thread because that is far more interesting and productive.

I'm glad Shannow (and a few others) haven't given up. They're the only one's that give this site any credibility.

 

[Oil Changer]

Originally Posted By: OVERKILL
"home chemist: the oil game" brings with it "no issues", tossing out anecdotes as proof of their mantra, seemingly oblivious to what Shannow posts on the subject.

And this happens EVERY TIME

But "She just loves it" and "She runs so smooth and quiet" and "She just eats it up"...

 

[Dallas69]

So you guys think any engine damage will occur because of mixing?
I think any SN rated oil is fine mixing with another SN oil
Yes or no

 

[OVERKILL]

Originally Posted By: Dallas69
So you guys think any engine damage will occur because of mixing?
I think any SN rated oil is fine mixing with another SN oil
Yes or no


In Texas, you are probably fine. In Alaska, there is the potential for the blend to seriously compromise the cold flow characteristics of the end product resulting in a situation where the oil may not pump. If that happens, well, yes, you'd have engine damage. Pretty severe engine damage.

 

[Shannow]

Originally Posted By: Dallas69
So you guys think any engine damage will occur because of mixing?
I think any SN rated oil is fine mixing with another SN oil
Yes or no


Put another way...do YOU think that every blend will be at least as good, and meet the same specifications as it's components ?

Yes or no ?

 

[wemay]

Its difficult to challenge years of practical use that has proven itself to be successful in not causing noticeable damage after so many miles. That has to be taken into account when discussing this subject. Shannow's contribution(s) are well received by many of us and appreciated. But those years of practice mean something to those who've used this method 'successfully'. This is not an affront to Shannow or the tests referenced.

 

[Dallas69]

Yes
I have never heard of any engine damage due to mixing
If there was I am sure someone here would've spoken up
Of course the oil companies always put in the "but" when asked about this-they want to sell more of their own brand
I truly believe that for 99% of the cars on the road that mixing any API certified oils is fine
I'm also sure that most folks on here at one time or another have mixed
I would be very surprised if I am wrong
I don't think the mixed oils turn into anything but oil

 

[Shannow]

wemay,
no offence taken anywhere.

Lack of things blowing up is taken on this site too often as proof of benefit...in so many areas, not just this one.

"Show me the pile of failed engines" is not proof that a practice (any practice) is beneficial.

I've been a mixer for the last 30 years, being put onto it through Vizard's books,and not being able to afford in the day full OCIs worth of M1...

I was a little shocked at what the "miscibility" standard actually offered versus what it was being promoted as on the board, particularly when read across the base oil interchange guidlines and what testing was required to even claim SN if you make your own syn blend.

I'm more circumspect regarding mixing having done my reading...that said, there's a blend in my Nissan, that I made up with closeout oils last June (before my reading), and it will stay for the full OCI....doesn't matter if 4 5Ws don't make a 5W when I can't get below -10C.

I now have a plan that is to buy Edge 5W30 on special, and avoid blending by keeping one target oil in my stash.

 

[wemay]

Originally Posted By: Shannow
wemay,
no offence taken anywhere.

Lack of things blowing up is taken on this site too often as proof of benefit...in so many areas, not just this one.

"Show me the pile of failed engines" is not proof that a practice (any practice) is beneficial.

I've been a mixer for the last 30 years, being put onto it through Vizard's books,and not being able to afford in the day full OCIs worth of M1...

I was a little shocked at what the "miscibility" standard actually offered versus what it was being promoted as on the board, particularly when read across the base oil interchange guidlines and what testing was required to even claim SN if you make your own syn blend.

I'm more circumspect regarding mixing having done my reading...that said, there's a blend in my Nissan, that I made up with closeout oils last June (before my reading), and it will stay for the full OCI....doesn't matter if 4 5Ws don't make a 5W when I can't get below -10C.

I now have a plan that is to buy Edge 5W30 on special, and avoid blending by keeping one target oil in my stash.


Understood

 

[fdcg27]

I ran 10W-40 in all of our cars for many years.
I started cars using this grade that had spent the night out of doors at ambients as low as -27F.
I never lost an engine.
That doesn't mean that this was a best practice.
When we learn of potentially bad results from what we've done for many years, we should consider changing our practices.
No reason that I can see to mix brands and grades of oil, other than to use up an odd quart or two.
This can be done for a summer run, where there should be minimal harm from any potentially bad interactions between different VIIs.

 

[BHopkins]

Originally Posted By: Shannow
wemay,
no offence taken anywhere.

Lack of things blowing up is taken on this site too often as proof of benefit...in so many areas, not just this one.

"Show me the pile of failed engines" is not proof that a practice (any practice) is beneficial.

I've been a mixer for the last 30 years, being put onto it through Vizard's books,and not being able to afford in the day full OCIs worth of M1...

I was a little shocked at what the "miscibility" standard actually offered versus what it was being promoted as on the board, particularly when read across the base oil interchange guidlines and what testing was required to even claim SN if you make your own syn blend.

I'm more circumspect regarding mixing having done my reading...that said, there's a blend in my Nissan, that I made up with closeout oils last June (before my reading), and it will stay for the full OCI....doesn't matter if 4 5Ws don't make a 5W when I can't get below -10C.

I now have a plan that is to buy Edge 5W30 on special, and avoid blending by keeping one target oil in my stash.


Shannow,

Thanks so much for your posts. I read the information on the links. All except one link in the linked discussion, that was no longer valid.

I find it very telling that, while you provided links to information that would suggest caution when blending motor oils, you do so yourself, and have for quite some time. There is a lot of strong critique here of those who imply that blending is safe because it has been done by many with no terrible results. However, doesn't all these experiences sum up to a level of evidence, that perhaps it is a safe practice? With all those here that have so much experience, and not a single "I lost the bearings in my engine after I started blending brand X and brand Y", doesn't that also add to the evidence?

I get your point, that failed engines is not proof that the practice is beneficial. But, when combined with the other evidence, the claims of clean engines. The claims of favorable UOA of blended oil. then, doesn't it add a validation to those?

When I consider that even you, who provided the links that may suggest that the oil companies aren't necessarily recommending blending, also blends, and has continued to do for, for three decades, I tend to lean towards adding a quart of PP to the RP for this single oil change. Not only you, but many others of our most experienced and knowledgeable members here. Those such as Clevy and Caterham 7. But, if I am missing something in the words of caution, would you please stick my nose in it and rub it around a bit.

 

[bbhero]

I have not mixed oils since I really started taking care of my cars a lot better than I did in my teens and early twenties. Since then I have not mixed my oil in my car per each oil change run. I have changed brands a good number of times but once it is changed I would top off with what I put in at the start of a run. Now I know there is some slight mixing because not 100% of the previous oil drains out. So a bit of mixing there albeit a very small amount. I will say this.. I have learned a good amount from a number of people who post on here.. Shannow, wemay, clevy, garak, caterham, car51 and a number of others too. So, I enjoy reading and learning from a lot of other people. Now if we were talking healthcare stuff than well.. I can help with that

 

[Shannow]

BHopkins,
I've been called a hypocrite on these forums for suggesting that blanding is not "best practice", while having a blend in the vehicles in my sig...your post is much more conciliatory, thanks.

The chances of something "bad" to "very bad" are quite small, I'll grant that...that's why I haven't dumped the brew in my Nissan, and will see out the full oil change.

Bad to very bad CAN happen, and are documented, most typically in the loss of cold temperature performance...I don't get below -10/11C,ever, so don't think I'll be stretching my 5W frankenbrew made of close-out components.

The standard is "mixable", and were I to make a brew, and name it Shannow blend, I could not claim legally that it even meets SN without doing certain tests again...they are the rules from the API regarding component interchange.

Largely, I think the reason that there are so few reported "bad" events is because the typical driver is not using the extreme cold end of their oil's pumpability range on a regular basis.

Provided that you are aware that the blend is likely not as good as either of it's components, and as long as you are not exploring the extremes of the cold temperature performance.

Top up or using up leftovers...versus intentionally setting out to be an oil formulator (what I used to do) are different things.