mixing oils can eat your engine?

[buster]

The case for improving VI falls along the same line of thinking.

"When you mix golf balls and basketballs, you don't get softball sized spheres - you get a physical (not chemical), mixture of golf balls & basketballs. When you mix a low molecular weight oil with a high molecular weight oil you get a physical mixture with molecules of different sizes. The extreme temp properties of those mixtures can't be determined "a priori" (theoretically), only by experiment." - TS

 

[BlueOvalFitter]

Originally Posted By: 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.

In my 97 F150 I would mix 10W30 Chevron Supreme with Super Tech 5W30 synthetic, CS with Havoline 10W30, CS with Pennzoil Conventional 5w30, and CS with Mobil 1 5W30. I mixed them because they were available to me, except for the Super Tech; I bought that to intentionally mix with the CS. The truck is still running with 267K miles.

 

[Garak]

Originally Posted By: buster
But it's extremely foolish to blend something like RL with say PU due to the fact that the chemistry is so different.

Yep, I wouldn't even want to be bouncing back and forth between the two brands OC to OC.

@BlueOvalFitter: Here are two more scenarios where I'd say there's a real reason (rather than a phobia) not to be bouncing around brand to brand. If one is looking to extend OCIs significantly, one should be sticking to one variety. I wouldn't be alternating between Mobil 1 Extended Performance and AMSOIL Signature Series, even though they are both extended drain oils. I'd pick one and stick with it. Also, if I had some weep or something I were addressing with MaxLife, I'd try to stick with it, rather than MaxLife once, then GTX, then Pennzoil conventional, then back to MaxLife.

Basically, if you're using an oil for a specific purpose, unless that purpose changes or the oil fails at that goal, there's no reason to change varieties.

 

[BlueOvalFitter]

Originally Posted By: Garak
Originally Posted By: buster
But it's extremely foolish to blend something like RL with say PU due to the fact that the chemistry is so different.

Yep, I wouldn't even want to be bouncing back and forth between the two brands OC to OC.

@BlueOvalFitter: Here are two more scenarios where I'd say there's a real reason (rather than a phobia) not to be bouncing around brand to brand. If one is looking to extend OCIs significantly, one should be sticking to one variety. I wouldn't be alternating between Mobil 1 Extended Performance and AMSOIL Signature Series, even though they are both extended drain oils. I'd pick one and stick with it. Also, if I had some weep or something I were addressing with MaxLife, I'd try to stick with it, rather than MaxLife once, then GTX, then Pennzoil conventional, then back to MaxLife.

Basically, if you're using an oil for a specific purpose, unless that purpose changes or the oil fails at that goal, there's no reason to change varieties.

Ok, fair enough. But oil is a lubricant and at the end of the day mixed can work just as well as not.

BTW, I have an OCI of Havoline 5W30 that is going in my 07 next. Opinions?

 

[demarpaint]

Originally Posted By: buster
The case for improving VI falls along the same line of thinking.

"When you mix golf balls and basketballs, you don't get softball sized spheres - you get a physical (not chemical), mixture of golf balls & basketballs. When you mix a low molecular weight oil with a high molecular weight oil you get a physical mixture with molecules of different sizes. The extreme temp properties of those mixtures can't be determined "a priori" (theoretically), only by experiment." - TS


Great point, all a viscosity calculator is mathematically giving you a number for viscosity. So what he's saying is, the end product might or might not be very good chemically. Certainly food for thought. As far as a $25 used oil analysis telling you if the mix is good probably isn't a good way to judge either?

 

[Garak]

Originally Posted By: BlueOvalFitter
Ok, fair enough. But oil is a lubricant and at the end of the day mixed can work just as well as not.

In the grand scheme of things and under anything approaching normal usage, absolutely. I don't think you'll find the slightest statistically significant difference in normal usage when switching or even mixing is involved, assuming that each lubricant choice was appropriate in the first place.

With respect to the Havoline, I would use that in a heartbeat, too. It's a little harder to get up here. It's regular price is relatively attractive compared to other brands, but finding it on sale is really difficult.

 

[danthaman1980]

These 'mixing' threads are hilarious.

buster, FYI some of us are chemists, scientists, tribologists, engineers, etc - and many of these people see benefits to mixing oils at times.

I'll be the first to admit that a poorly thought-out mix could do more harm than good (I wouldn't mix a Group V base with a Group II base, nor an API SG with API SN, nor a 0W-20 with a 10W-60). But mixing similar oils to get something in between is nothing to be afraid of. If my experience tells me that xW-30s are a little too thin and xW-40s are a little too thick for my 200,000+ mile engine, why not mix them half and half to get something in between?

Look - every motor oil on the market is not tested in every type of engine ever built. Your favorite 5w30 might be the absolute best thing for your engine - but odds are it was designed to work in a broad range of climates in a broad range of engines, it was designed to compete in the current marketplace so it must not cost too much, and it was designed so that it can be manufactured easily. That design might be the bee's knees in your motor - or it might just be 'good', not 'great'.

If you happen to own an engine that had a specific motor oil designed around it, consider yourself lucky - you can go buy the best oil for your engine without worrying about it.

 

[buster]

The most hilarous part of mixing threads is this idea that Joe Schmoe can create a better oil by mixing brands that use different additives/base oils. How does one do that, and determine it's better?

 

[DragRace]

Originally Posted By: buster
The most hilarous part of mixing threads is this idea that Joe Schmoe can create a better oil by mixing brands that use different additives/base oils. How does one do that, and determine it's better?

Always wondered that myself!

 

[Cup of Joe]

Originally Posted By: buster
The most hilarous part of mixing threads is this idea that Joe Schmoe can create a better oil by mixing brands that use different additives/base oils. How does one do that, and determine it's better?

We know its better by several long minutes of oil pressure monitoring. We are absolutely certain this mix is far superior to any off the shelf product. Our butt dyno confirms this everytime.

 

[BlueOvalFitter]

I only mixed because the oil was available. And when I did buy an oil and mixed it was because it was in limited supply on the shelf. ST used to be so cheap and everyone wanted it.
And, who is it really bothering if someone mixes oil? Man, I have seen women's claws come out in less controversial issues than this.

 

[buster]

Originally Posted By: TaterandNoodles
Originally Posted By: buster
The most hilarous part of mixing threads is this idea that Joe Schmoe can create a better oil by mixing brands that use different additives/base oils. How does one do that, and determine it's better?

We know its better by several long minutes of oil pressure monitoring. We are absolutely certain this mix is far superior to any off the shelf product. Our butt dyno confirms this everytime.



LOL

 

[buster]

Originally Posted By: BlueOvalFitter
I only mixed because the oil was available. And when I did buy an oil and mixed it was because it was in limited supply on the shelf. ST used to be so cheap and everyone wanted it.
And, who is it really bothering if someone mixes oil? Man, I have seen women's claws come out in less controversial issues than this.





Hey, mix away. I could care less. I'm justmaking a point about differences in oil chemistry and unkown brew you get. Have at it.

 

[BlueOvalFitter]

Originally Posted By: buster
Originally Posted By: BlueOvalFitter
I only mixed because the oil was available. And when I did buy an oil and mixed it was because it was in limited supply on the shelf. ST used to be so cheap and everyone wanted it.
And, who is it really bothering if someone mixes oil? Man, I have seen women's claws come out in less controversial issues than this.





Hey, mix away. I could care less. I'm justmaking a point about differences in oil chemistry and unkown brew you get. Have at it.

I haven't mixed oils in 6 years. But if it will raise the hair on some members necks here, then it might be worth it.

 

[BlueOvalFitter]

Originally Posted By: BlueOvalFitter
I haven't mixed oils in 6 years. But if it will raise the hair on some members necks here, then it might be worth it.

Hmmm, seems I stretched the truth there a bit. I made a salad dressing last week and mixed Canola oil with Extra Virgin Olive oil. I hope I live to do it again.

 

[Cup of Joe]

Originally Posted By: BlueOvalFitter
Hmmm, seems I stretched the truth there a bit. I made a salad dressing last week and mixed Canola oil with Extra Virgin Olive oil. I hope I live to do it again.

I believe that is a misdemeanor unless they can prove you mixed them with the intent to create something delicious.

 

[BlueOvalFitter]

Originally Posted By: TaterandNoodles
Originally Posted By: BlueOvalFitter
Hmmm, seems I stretched the truth there a bit. I made a salad dressing last week and mixed Canola oil with Extra Virgin Olive oil. I hope I live to do it again.

I believe that is a misdemeanor unless they can prove you mixed them with the intent to create something delicious.

LOL!

 

[Garak]

Originally Posted By: danthaman1980
I'll be the first to admit that a poorly thought-out mix could do more harm than good (I wouldn't mix a Group V base with a Group II base, nor an API SG with API SN, nor a 0W-20 with a 10W-60). But mixing similar oils to get something in between is nothing to be afraid of.

That's the thing. Unless I were to be fairly certain the mix I would be coming up with would be more advantageous to me than anything off the shelf, I'd be hesitant.

I'd be more likely to explore at the margins of what's actually available on the shelf. Like you said, if your experience tells you that the average API/ILSAC xw-30 is a little too thin for what you want, and the average 40 grade is too thick, instead of mixing, I'd be looking at something like GC, a multigrade HDEO in a 30 range, possible a High Mileage oil or Defy, or a light 40 (like Mobil 1 0w-40). But, that's just me trusting the oil companies to know more about it than I do.

Now we need to make the world's first open source oil. It will be the mixers' delight.

 

[zanzabar]

WOW - you guys are going off the deep end here! Let's be realistic, the reason for mixing oils for the vast majority of people that do it is simply because they get "too heavy oil X" on sale and "too light oil Y" on sale and they just happen to need something in between. Especially when you load up on a sale item and have 10 gallons of oil sitting around in your garage (I'm one of these people), there's no reason to go out and pay for new oil when you can brew up a batch of X+Y and make it close enough to the viscosity recommended for the vehicle/climate.

Is it going to damage your engine? NO! We all know you shouldn't do extended drains on this stuff so what's the big deal?

To provide evidence that I'm in the wrong, please find a used oil analysis of a frankenbrew that didn't turn out well. We can find dozens of ones that were fine, but I' have never seen evidence of this "additive clash" in a used oil analysis.

 

[zanzabar]

Quote:
Originally posted by MolaKule:
Most of the additives used in modern oils are soluble in just about any base oil.

I have yet to see any additive clash in modern, fuly formulated oils, even when mixed.

https://bobistheoilguy.com/forums/threads/quantifying-additive-clash.8531/