Pep Boys warns Not to mix oils.

[Merkava_4]

Originally Posted By: veryHeavy
He wrote on my bill:

!!!CUSTOMER BROUGHT 4 DIFFERENT QUARTS OF OIL !!! ADVISED NOT A GOOD IDEA TO MIX OIL AND WEIGHTS !!!!


Did the guy really write it in all capital letters like that ?

 

[kschachn]

Originally Posted By: veryHeavy
!!!CUSTOMER BROUGHT 4 DIFFERENT QUARTS OF OIL !!! ADVISED NOT A GOOD IDEA TO MIX OIL AND WEIGHTS !!!!


He's correct that it's not a good idea. As Shannow has pointed out multiple times, it is only guaranteed that no bad things will happen, but that doesn't mean anything good will happen either. All you can say is that they are miscible with no additive clash.

What you do end up with is an oil with uncertain cold temperature performance and no certifications.

 

[kschachn]

Originally Posted By: KL31
I can't believe this has not been debunked and people still think it's an issue. Even after all the VOA and used oil analysis here of mixed oils AND the complete and lack of engine death due to mixing.


What parameters of a used oil analysis (or a VOA for that matter) would you look at to determine if it is OK to mix two oils?

 

[PeterPolyol]

Originally Posted By: kschachn
but that doesn't mean anything good will happen either.


Sure it does! The "good" that happens is that one can complete a job economically, without any further worry, cost or known detriment, and move on.

Originally Posted By: kschachn

What parameters of a used oil analysis (or a VOA for that matter) would you look at to determine if it is OK to mix two oils?


Likewise without comparing additive package proportions from previously known data, what parameters of a used oil analysis/VOA would, by themselves, suggest that one has a blend of multiple branded oils?

 

[kschachn]

Originally Posted By: PeterPolyol
Originally Posted By: kschachn
What parameters of a used oil analysis (or a VOA for that matter) would you look at to determine if it is OK to mix two oils?

Likewise without comparing additive package proportions from previously known data, what parameters of a used oil analysis/VOA would, by themselves, suggest that one has a blend of multiple branded oils?


That's a silly question. My comment was to the poster that said a history of used oil analysis proves that it is OK to mix.

Once again, what would it be in that used oil analysis that would show this?

 

[PeterPolyol]

Originally Posted By: kschachn
Originally Posted By: PeterPolyol
Originally Posted By: kschachn
What parameters of a used oil analysis (or a VOA for that matter) would you look at to determine if it is OK to mix two oils?

Likewise without comparing additive package proportions from previously known data, what parameters of a used oil analysis/VOA would, by themselves, suggest that one has a blend of multiple branded oils?


That's a silly question. My comment was to the poster that said a history of used oil analysis proves that it is OK to mix.

Once again, what would it be in that used oil analysis that would show this?


The question isn't silly if it leaves the detractor no other choice but to concede that a used oil analysis shows nothing, one way or the other, in relation to mixing oils.

If anything's silly, it's to ask a strategically skewed rhetorical question non-rhetorically with the expectation of a legitimate answer that you know is not there. used oil analysis are not magic 8-balls, they don't make recommendations; they don't sanction ideology. used oil analysis won't tell you it's okay to mix oils, exactly as they will not tell you it's not okay to mix oils. There is nothing specific about, or any data expected out of, a used oil analysis that relates to mixing fundamentally compatible finished consumer lubricants. The only thing the data in a used oil analysis is expected to provide insight on, is of the lubricant's condition and that the lubricant is performing as expected. Why should you challenge kl31, or anyone, for mentioning their used oil analysis that demonstrate to their satisfaction that the lubricant performed as expected?

 

[kschachn]

Originally Posted By: PeterPolyol
used oil analysis are not magic 8-balls, they don't make recommendations; they don't sanction ideology. used oil analysis won't tell you it's okay to mix oils, exactly as they will not tell you it's not okay to mix oils. There is nothing specific about, or any data expected out of, a used oil analysis that relates to mixing fundamentally compatible finished consumer lubricants.


Thanks for the answer at least.

 

[Shata]

I'm just going to say this everyone around here that mixes some witches brew of oils doesn't do it with their 40-50k cars or trucks. If you have beater daily that ur running into ground okay and I would like to say people that are mixing that is the case.

 

[fdcg27]

Originally Posted By: Shata
I'm just going to say this everyone around here that mixes some witches brew of oils doesn't do it with their 40-50k cars or trucks. If you have beater daily that ur running into ground okay and I would like to say people that are mixing that is the case.


You appear to understand the whole thing, unlike some of the other newbies who want to argue with more knowledgeable members that mixing is benign.

 

[ebr1190rx]

Lol I mix in all of my vehicles. I like pao and poe and moly shots on top of plain jane synthetics. My bike, yukon denali , turbo sonata, old beater sbc s-10 , jeep gc limited 5.2, boat mercruiser 350 magnums; all running mixes.

 

[Nickdfresh]

On the whole it's probably better not to mix and to use the same weight/brand of oil at the beginning of an OCI. However, the manager's reaction was wholly unprofessional and bordering on histrionic. The U.S. military long ago demanded that all PCMO and HDEO be compatible, at least. Is mixing optimal? No IMHO. Should a manager of any service center go on a tirade complete with panicky messages? No. He's just dumb...

 

[Shannow]

Problem is that the "compatibility" test is only that they can be mixed (with 7 reference oils), frozen, heated, and frozen again without reating together, precipitating something out, or splitting like salad dressing...not that any othe performance parameter is maintained.

It's essentially the chemical equivalent of "nothing blew up"

 

[aquariuscsm]

Originally Posted By: Merkava_4
Originally Posted By: veryHeavy
He wrote on my bill:

!!!CUSTOMER BROUGHT 4 DIFFERENT QUARTS OF OIL !!! ADVISED NOT A GOOD IDEA TO MIX OIL AND WEIGHTS !!!!


Did the guy really write it in all capital letters like that ?

Haha my guess would be yes,while at the same time pounding the pen really hard while making all those exclamation marks,likely breaking the ballpoint and making holes in the paper

 

[CKN]

Originally Posted By: fdcg27
Originally Posted By: Shata
I'm just going to say this everyone around here that mixes some witches brew of oils doesn't do it with their 40-50k cars or trucks. If you have beater daily that ur running into ground okay and I would like to say people that are mixing that is the case.


You appear to understand the whole thing, unlike some of the other newbies who want to argue with more knowledgeable members that mixing is benign.



You guys got it so right. I'm waiting for someone to say they mix witches brew in a vehicle worth more than 20grand. We will be waiting a while.......

 

[Sonic]

My 2015 Subaru Legacy Limited has a mix in it now. I'm 4000 miles into the OCI. I've mixed for years and can't tell the difference. I'm not saying I'm making something better, I just can't stand having tons of partials sitting around. IIRC my Legacy has 3qts Mobil 1 5w20, 1qt Napa 0w20, 1qt of Defy 5w30.

 

[blupupher]

Originally Posted By: CKN
I'm waiting for someone to say they mix witches brew in a vehicle worth more than 20grand. We will be waiting a while.......

Not too long.
I would, did and will continue to do just that.
I have mixed M1 with Valvoline conventional (both 5w30) in a $20,000+ Trailblazer. Mobil 5000, 1 qt M1, and 1 qt Pennzoil Platinum once and then Valvoline conventional, Valvoline Durablend and M1 another time in a $20,000+ Grand Caravan, I know I mixed brands and weight (5w30 and 10w30) several times in a $20,000+ Dodge Ram.
Not sure why vehicle value makes a huge difference in if someone would do it or not. I treat my new vehicles the same as my old ones. I want them to last as long as possible, regardless of value.
Sure I try to stick with one oil during an oil change, but extra bottles need to be used at some point. As said before, how many add a qt of top off oil that is different than what was used at the oil change with no ill effects?

My brews have almost always been to use up what is left over, once did I mix purposefully to make a syn blend (same brand and weight, just a 50/50 conventional/syn blend), and once mixed some xw-20 to thin out some xw-40 that I had no other use for (different brands also, but both conventional oil).
Heck, my truck (not worth $20,000+, so I guess some would say it is a beater?) has a brew in it. Why, because I had 3 qts of 5w-20 Nextgen and needed 6 for the oil change, so I used some 5w-20 Pennzoil Platinum I had laying around to get 6 qts. I could have used 3 qts of several other oil in my stash (12 qts Castrol GTX Blend, 15 qts Quaker State Synthetic, 12 qts Havoline HM, 10 qts Valvoline Syn, 5 qts Mobil 1 Advanced Fuel Economy, 6 qts Auto Zone Syn) but it would have made me short on oil changes later on. I am not trying to accomplish anything except use oil that I have.


As for the OP, the manager is just covering his rear. I mean they did do it after all.

 

[CT8]

Originally Posted By: CKN
Originally Posted By: fdcg27
Originally Posted By: Shata
I'm just going to say this everyone around here that mixes some witches brew of oils doesn't do it with their 40-50k cars or trucks. If you have beater daily that ur running into ground okay and I would like to say people that are mixing that is the case.


You appear to understand the whole thing, unlike some of the other newbies who want to argue with more knowledgeable members that mixing is benign.



You guys got it so right. I'm waiting for someone to say they mix witches brew in a vehicle worth more than 20grand. We will be waiting a while.......
The company I worked for used their class 8 vehicle to use the odd and end oils from the service vans. The company would use Delo 400 in everything but the mechanics in the field would sometimes run out of oil and would buy what ever HDEO was at the parts store and during inventory time the non Delo would be switched out for Delo and that what was used in the big truck . 10 or so gallons of oil and it was in Qts.

 

[fdcg27]

I've mixed even in cars that couldn't be considered beaters as well just to use up odds and ends, but I've done so only for warm weather runs, since the cold performance of any mix is unknowable.
Not much of a problem in most of Cali.
Beaters are entitled to best practices as well, though. Why would anyone want to shorten the life of even a beater?

 

[Ducked]

I've had a mix of straight 40 and 15w40 in for a couple of years now. That was an emergency response to an oil leak, but I'm starting to think it might be a good compromise, though it is an unknown.

n the past, I've topped up with small amounts of straight 40, the rationale being that this will compensate for viscosity loss due to VI shearing.

The manager was right to caution the customer. He just overdid it a bit.

 

[weebl]

I've mixed oil brands and viscosities for as long as I can remember, and boy, every time I've done it, I've had an engine blow up, my dog run away, termites eat my house and found the boogie man hiding under my bed.

Seriously, there have been absolutely ZERO issues.

What it has done is allow me to use up leftover oil from past changes. I don't go out of my way to mix, but do it when it makes sense.