mixing oils can eat your engine?

[antiqueshell]

Originally Posted By: buster
All oils are compatible, but you should try and stick with one brand and don't let anyone tell you differently. Despite what most folks think it's not a good idea to switch back/forth between brands. I've heard this directly from a formulators mouth. Detergents can often interact with each other in a negative way. Won't hurt, but you're better off sticking with one brand.

You can switch as much as you like and are not likely to cause any serious problems, but sticking with one brand is preferable.

For example, Castrol's detergent system is nothing like Pennzoil's so there will be interaction between the two and they often don't mix well. Compatible, yes, but not ideal.



I'm not buying this.

Although I wouldn't deliberately mix oil when I do an oil change, it's ludicrous to think that any tangible issues would occur from changing brands from OC to OC.

Can you provide us with the "formulator" that provided you with this information?

 

[surfstar]

NO ONE SAID IT CAUSED HARM TO YOUR ENGINE!!!

All that was said, is that there may be less wear / and/or benefits to sticking with one brand that has the same chemistry / add pack / etc.

I could point to all the threads: "I just changed to ___ oil and now I have startup noise"

From what I remember, it was stated that the AW additives build up protection and changing brands could break down this protective layer before building up the new one - PARAPHRASING. It won't kill your engine. It won't affect engine life.

If you want to hear what I did - look up the Adam Carolla Carcast podcast from sometime (late last year?) with the guy from Joe Gibbs Racing Oils on it - I'm trying to paraphrase what I remember him saying.

[edit] found it: http://www.adamcarolla.com/CarCastBlog/2012/07/synthetic-oil-with-lake-speed-jr-audi-r8/ listening now to see what it did indeed say

This is not a BITOG level podcast - its meant for laymen and I'm sure you guys could start a new thread picking it apart!

 

[surfstar]

Well, listening again, the JG guy is Lake Speed Jr and says its better/important to stick with one brand, but doesn't get much more technical than that!

Whatever.

I believe it would make no discernible difference either way. Another BITOG nitpick...

 

[askani79705]

4 quarts Rotella 10w30 and 2 quarts Castrol Syntec in my 97 F150 right now.I mix in it often to use up remnants of other changes.I guess this means I'm screwed.

 

[BlueOvalFitter]

Originally Posted By: ted s
read this on the Mustang Club of America forum:

ford changed my oil. I had synthetic put in and they set my next oil change in 10,000 miles so listen up guys this guy tells the truth. Reminder never mix different brands of synthetics. they turn to acid and eat your engine.

What a load.

 

[surfstar]

So...

Similar question (to no one in particular):
If you had to mix two grades for whatever reason (due to your wanted viscosity or $/availability, etc)...

Do you agree that it makes more sense to mix oils within the same brand?

The add pack is similar throughout a brand, right? Wouldn't it make the most sense to keep that carefully derived formula that chemical engineers spend a lot of research coming up with vs combining oils from two different brands?

I've mixed and topped off with whatever and there's no harm. But is there a benefit to matching the add packs?

Mola - input?

 

[DragRace]

This forum lately is starting to be less informational and more full of garbage like threads such as this one.

 

[BlueOvalFitter]

Originally Posted By: surfstar
So...

Similar question (to no one in particular):
If you had to mix two grades for whatever reason (due to your wanted viscosity or $/availability, etc)...

Do you agree that it makes more sense to mix oils within the same brand?

The add pack is similar throughout a brand, right? Wouldn't it make the most sense to keep that carefully derived formula that chemical engineers spend a lot of research coming up with vs combining oils from two different brands?

I've mixed and topped off with whatever and there's no harm. But is there a benefit to matching the add packs?

Mola - input?

The 97 F150 I used to own is still running. My friend I sold it to says it now has 267K miles. It survived 98K miles of my oil mixing chemistry.

 

[surfstar]

Originally Posted By: BlueOvalFitter
Originally Posted By: surfstar
So...

Similar question (to no one in particular):
If you had to mix two grades for whatever reason (due to your wanted viscosity or $/availability, etc)...

Do you agree that it makes more sense to mix oils within the same brand?

The add pack is similar throughout a brand, right? Wouldn't it make the most sense to keep that carefully derived formula that chemical engineers spend a lot of research coming up with vs combining oils from two different brands?

I've mixed and topped off with whatever and there's no harm. But is there a benefit to matching the add packs?

Mola - input?

The 97 F150 I used to own is still running. My friend I sold it to says it now has 267K miles. It survived 98K miles of my oil mixing chemistry.

That didn't answer my question. I am narrowing it down more, as I know it won't hurt anything - but do people agree that it makes more sense to mix within a brand?


Oh, and I agree that this thread was [censored] for the first half (the OP, etc), I only noticed it starting with buster's post: #3000991 - 05/13/13 12:48 PM

Almost should be split off it so different.

 

[Garak]

Originally Posted By: surfstar
Do you agree that it makes more sense to mix oils within the same brand?

The add pack is similar throughout a brand, right?

Maybe, but not necessarily. Mobil Super conventional and Castrol GTX use sodium additive packages. As far as I recall, M1 and Syntec do not.

And yes, Buster's comment is worth noting. As I've mentioned before, the miscibility/compatibility rules of the API and ILSAC specs are probably in place to ensure that you don't have an issue topping up with GTX 20w-50 at the gas station when your oil change was originally Pennzoil Conventional 5w30.

It wasn't designed so you could play pin the tail on the donkey in the oil aisle.

 

[BlueOvalFitter]

Originally Posted By: Garak
Originally Posted By: surfstar
Do you agree that it makes more sense to mix oils within the same brand?

The add pack is similar throughout a brand, right?

Maybe, but not necessarily. Mobil Super conventional and Castrol GTX use sodium additive packages. As far as I recall, M1 and Syntec do not.

And yes, Buster's comment is worth noting. As I've mentioned before, the miscibility/compatibility rules of the API and ILSAC specs are probably in place to ensure that you don't have an issue topping up with GTX 20w-50 at the gas station when your oil change was originally Pennzoil Conventional 5w30.

It wasn't designed so you could play pin the tail on the donkey in the oil aisle.

What are the advantages of a sodium additive package?

 

[demarpaint]

I was from the school of thought that Buster mentioned. Although I was also told it wouldn't harm an engine switching brands, it was also suggested once I found a good brand that I was happy with to try and stick with it. Having said that I've been changing brands more than I typically do, but that's changed again and I should be sticking to one brand at least for now.

 

[virginoil]

Two lines of mis truths generated 51 replies.

If mixing synthetics was a problem BITOG would have shutdown a long time ago.

How many engine failures from mixing brands reported on this site since 2002 ???

 

[Garak]

Originally Posted By: BlueOvalFitter
What are the advantages of a sodium additive package?

At least as per what Mola has told us, there's no real advantage. It's just a different way of doing things.

@demarpaint: Yep, I'm along similar lines. I don't mind switching once in a while, particularly if something happens to be on a good deal, or if I've got an overriding reason to switch (i.e. the days of summer/winter weights).

But, if I find a good deal and/or an oil I like, I buy a bunch of it, so I'm using it for a while. When I run out, I can buy more, if the price is reasonable again, or try something different.

If I'm switching, I prefer to have a reason why, rather than something random. If Brand X becomes too expensive or hard to find, that's a good reason to switch. If I can get Brand Y at a good, long term discount, that's another good reason to switch. If Brand Z seems noisy or comes in oddball container sizes, switch away.

To be clear, I would suggest that most oils out there are pretty darned fine (assuming they're certified and appropriate for the application). I'd be equally happy with Castrol GTX, Pennzoil Conventional, Quaker State Conventional, Formula Shell, Mobil Super, Mag 1, Havoline, Valvoline, or Super Tech. That doesn't mean I'm going to try them all at the same time, or even one after another.

 

[BlueOvalFitter]

Garak, do you think the switching of oil brands can do something to the contact points of the parts where the oil coats them? AKA, wash away the coating a said oil is made to do?

 

[Doog]

This whole acid thing is true...that is why there is wax in Pennzoil oil to help protect engine parts from the acid.

 

[buster]

No one said you can't mix oils of different brands. Of course oils change over time and you're going to get some residual oil left over when switching to another brand. But it's not ideal to mix.

The issue is people who think they are chemists can blend mutliple oils of different brands using different chemistries together. The facts are simple. Different oils often use different detergent systems. - Valvoline, Castrol, Pennzoil etc.

If you are making your own blend you're running the risk of using an oil that is not balanced and optimal for the engine. It's a simple as that. Of course all oils are compatible but mixing them is not ideal and it's never been.

This doesn't mean going from one brand to antoher is bad. It happens all the time. But thinking you can create your own superior blend is extremely naive.

 

[Garak]

Originally Posted By: BlueOvalFitter
Garak, do you think the switching of oil brands can do something to the contact points of the parts where the oil coats them?

No, but it might interfere with the wax layer laid down by Pennzoil, as Doog said.

Seriously, though, in extreme conditions, what you mention might be possible. I suspect, at least from a hypothetical standpoint, it would be easier to visualize if someone where using a very, very high ZDDP non-detergent racing oil and then switched to a high detergent synthetic PCMO. I'm certain the anti-wear layer would take a hit.

I can't see that happening from switching from one SN/GF-5 PCMO to another, really, other than what normally happens at oil change time anyhow. I have to admit my dislike of mixing is more of a phobia rather than a sensible reaction. My view is that I don't know more than the blender, and that additive packages aren't completely identical nor absolutely interchangeable, nor fitting with the philosophy of more is better.

To explain, perhaps it's better if I draw the line as to what I would and wouldn't do. I'd have no problem switching from Castrol GTX To Pennzoil Conventional or vice versa, over the long term (i.e. several oil changes of one, several of the other). I would not be happy with alternating between the two each oil change. If I were in a synthetic mood, I certainly wouldn't want to be switching back and forth between Red Line and M1 each oil change, either.

As CATERHAM has pointed out though, there are reasonable ways to mix oils, and good reasons to do so. He likes to play with viscosities, and he is mixing oils that are optimal for that. I doubt he'd do a 50/50 mix of 20w-50 GTX and Pennzoil Conventional 5w20, even if he fell on his head and decided to do a strange viscosity blend; he'd probably stick with one brand or the other.

Realistically, though, I highly doubt that switching brands, even each and every oil change, is going to make the slightest bit of difference to the lifespan of an engine. Do recall that I got an Impala up to 1,000,000 km, with each and every oil change being Quaker State conventional and a Wix filter. So, I come from a viewpoint of "stick with what works."

See, all the guys here make my life very difficult. I'd like to try many different kinds of oil, but I have only so many vehicles and so many miles going on, and I don't like to switch, so I miss out.

By the way, one time when switching oils willy nilly would be counterproductive would be when trying to run a trended UOA program.

 

[Garak]

Originally Posted By: buster
The issue is people like CATERHAM, who think they are chemists can blend mutliple oils of different brands using different chemistries together. The FACTS are simple. Different oils often use different detergent systems. - Valvoline, Castrol, Pennzoil etc. When you mix them there can be issues. that is a fact.

I'm going to have to defend CATERHAM on this one, and you know what I think about blending.

I think his "different brand" blending is fairly minimal. Some of the stuff he blends that has different labels is actually from the same blender. I don't think he'd be quick to mix Pennzoil Conventional and Red Line, or Valvoline and QS, either.

@BlueOvalFitter: I just remembered where I do jump around more often. My OPE happens to get whatever leftovers are lying around. My snowblower went from an orphaned Syntec quart to a MaxLife one, and will likely get Mobil 1 5w30 or RP 0w-40 next.

I go through so little oil in OPE that trying to stick to one brand and avoiding reformulations of that variety would be logistically difficult. I always have these "extra quarts" laying around since I had a lot of oil burners in my youth and always buy more than I needed for an oil change.

 

[buster]

Quote:
think his "different brand" blending is fairly minimal. Some of the stuff he blends that has different labels is actually from the same blender. I don't think he'd be quick to mix Pennzoil Conventional and Red Line, or Valvoline and QS, either.


I'm ok with that. If you're staying within the same oil family and just blending for viscosity reasons that's fine. But it's extremely foolish to blend something like RL with say PU due to the fact that the chemistry is so different. Different moly, detergetns etc. And in different %'s.