Walmart Oil Change?

[OVERKILL]

You are greatly over-thinking this.

Oil by itself doesn't go bad. It gets diluted with fuel, wear metals, combustion byproducts...etc and is required to keep acids neutralized and those contaminants in suspension. As long as those things can be done successfully, it will continue to be serviceable. When you change the oil, a small amount of residual lubricant, laden with the amount of contaminants that was consistent with the entire sump contents before it was changed, remains. Note that you've removed >80% of those contaminants with the change. Upon fire-up with fresh oil, those contaminants are immediately diluted in the new oil and cease to become relevant. Then the process repeats as the engine is operated. As long as the lubricant is not operated beyond its ability to perform those tasks, you will not experience sludge or other negative consequences.

 

[csandste]

Wal-Mart is scrupulous about putting in the exact called for amount of oil, even charging my girl friend for the extra tenth of a quart, 5.1. Always slightly over filled cause filter is smaller than OEM and they're in a hurry. No big deal.

 

[FordBroncoVWJeta]

Originally Posted by spk2000
Walmart now does vacuum up the diptstick tube only.

Not true. They actually trying to stay away from it as it takes too long. Depending on the store of course. My store we pretty much disabled the EVAC because it took way too long.

 

[Rolla07]

Whens the last time you killed an engine before scrapping a car?

 

[Talent_Keyhole]

Originally Posted by Lubener
Originally Posted by tundraotto
You need to worry about new things. Oil is fine.

+1


How would you know the oil is fine? Would retention of 5ppm of iron wear, loss in viscosity, fuel dilution, loss in TBN within minutes of mixing of oil is not a concern?

 

[Talent_Keyhole]

Originally Posted by spk2000
Walmart now does vacuum up the diptstick tube only. So depending on the vehicle some are better suited for this than others. I tried my own vaccum oil out the dipstick tube on my old 93 Honda Civic and could only get 1 qt out. Theirs is probably better than that but you also have to consider who is doing it and are they in a hurry to get to break or off work or finish up so they can sit. You just never know unless you can watch them.


The two Walmart's in my area do not use vacuum extraction. They still spill and fill.

 

[OVERKILL]

Originally Posted by Talent_Keyhole
Originally Posted by Lubener
Originally Posted by tundraotto
You need to worry about new things. Oil is fine.

+1


How would you know the oil is fine? Would retention of 5ppm of iron wear, loss in viscosity, fuel dilution, loss in TBN within minutes of mixing of oil is not a concern?


No, it's not a concern. Say you have 5ppm of Fe. That's 5ppm over the entire sump volume. You remove >80% of that doing a change so you'd have at most 1ppm in the fresh fill. TBN would be at close to virgin...etc. You are talking an extremely small amount of already dilute product in the volume of used oil being mixed with entirely fresh, diluting it to the point of irrelevance.

 

[PimTac]

You are definitely worrying too much about this. However, if that oil is vile then I would change it.

 

[Talent_Keyhole]

Originally Posted by hallstevenson
Why include "Walmart" in the subject or even refer to it ? Everything you mention pertains to all oil changes, even "perfect" ones that people DIY.

That said, you're seriously overthinking this. Tell you daughter everything's fine and to change it when the OLM tells her to. I presume it goes 5000-8000 miles typically ?


Because I can....

Really, "overthinking". Would retention of 5ppm of iron wear, reduction in viscosity, fuel dilution, decrease in additives and loss of TBN within minutes of running the engine is not a concern. The last time I checked OLM do not monitor actual oil quality. Maybe someday they will detect fuel, and viscosity, soot levels, etc.

Correct, presumption. The OLM was at 10% after only 2900 miles,

 

[Talent_Keyhole]

Originally Posted by hallstevenson
Use a garage ? Even an unheated one will be warmer than directly outside. Our garage maintains 50-55º F if the outside temperature is in the 30s. Or, waiting a week or even a thousand miles for a bit warmer weather isn't going to make a difference. No car needs the oil changed right now.


How would you know that NO car needs a change RIGHT NOW? Some people do not have access to a garage? Interesting that you want to argue about the urgency of the oil change, but not the contamination of the new oil.

 

[Talent_Keyhole]

Originally Posted by OVERKILL
You are greatly over-thinking this.

Oil by itself doesn't go bad. It gets diluted with fuel, wear metals, combustion byproducts...etc and is required to keep acids neutralized and those contaminants in suspension. As long as those things can be done successfully, it will continue to be serviceable. When you change the oil, a small amount of residual lubricant, laden with the amount of contaminants that was consistent with the entire sump contents before it was changed, remains. Note that you've removed >80% of those contaminants with the change. Upon fire-up with fresh oil, those contaminants are immediately diluted in the new oil and cease to become relevant. Then the process repeats as the engine is operated. As long as the lubricant is not operated beyond its ability to perform those tasks, you will not experience sludge or other negative consequences.


Agree, oil generally does not go bad on its own. Some additives will fall out of suspension. Excess heat and contamination are major factors to oil degradation.

When a decision is made to change the oil, whether using the OLM or just distance/hours, what guarantee is there that the oil is serviceable, without completing a UOA?

Is it really irrelevant when the new mixture contains 5ppm wear metals, 10% drop in viscosity and TBN, decrease in additive levels and measureable levels of fuel dilution within minutes of use.

My wife's Chevy Aveo with 170K miles had the oil changed religiously every 3k miles. It has tremendous varnish, sludge, carbon build-up, and burns oil at unacceptable levels.

 

[4WD]

Good timing for me … my son is on long out of town assignment … so drove up to check the Cruze. Only needed a new battery, 4 new tires, a tank of gas (added Techron) and an oil change, LoL

I pulled in at Walmart and started for the door. Kid says what are you here for? So he said pull behind those 2 cars. Just as I start moving he walks up to a just arriving car and tells them to pull in ahead of me. I slammed on the brakes to avoid impact

Rolled down the window and said if we collided (was not my fault or the pull ahead, it was the kid) Walmart would be working with my insurance company or my lawyer and headed for Jiffy
(naturally Jiffy was 150' from the DT I had left 20 minutes back, brand new store, great staff and great layout)

 

[Talent_Keyhole]

Originally Posted by Rolla07
Whens the last time you killed an engine before scrapping a car?


My last two GM vehicles went through two engines each, with the transmission performing flawlessly for 250K miles. In this case the transmission was fully flushed, and all fluid, wear metals and contaminates were removed every 75K miles.

There is merit in full volume fluid exchanges for engines. It is well established, the cleaner the oil, the longer engine life. Replacing only 80% of the oil each in every time, I believe will shorten the engine life.

 

[Talent_Keyhole]

Originally Posted by OVERKILL
Originally Posted by Talent_Keyhole
Originally Posted by Lubener
Originally Posted by tundraotto
You need to worry about new things. Oil is fine.

+1


How would you know the oil is fine? Would retention of 5ppm of iron wear, loss in viscosity, fuel dilution, loss in TBN within minutes of mixing of oil is not a concern?


No, it's not a concern. Say you have 5ppm of Fe. That's 5ppm over the entire sump volume. You remove >80% of that doing a change so you'd have at most 1ppm in the fresh fill. TBN would be at close to virgin...etc. You are talking an extremely small amount of already dilute product in the volume of used oil being mixed with entirely fresh, diluting it to the point of irrelevance.


The original oil sump contained 25 ppm iron wear. The new mixture within a few minutes contained 5 ppm iron wear. Actually TBN dropped by 10% along with viscosity.

That is not irrelevant. Would you purchase new oil that had 5 ppm wear metals and have viscosity and TBN that did not meet new oil standards, and containing measurable fuel dilution. My guess is that would be NO and you and the average owner would be returning the product and calling customer service to file a complaint or reporting to PQIA. In fact such oil has been reported by them.

 

[Talent_Keyhole]

Originally Posted by 4WD
Good timing for me … my son is on long out of town assignment … so drove up to check the Cruze. Only needed a new battery, 4 new tires, a tank of gas (added Techron) and an oil change, LoL

I pulled in at Walmart and started for the door. Kid says what are you here for? So he said pull behind those 2 cars. Just as I start moving he walks up to a just arriving car and tells them to pull in ahead of me. I slammed on the brakes to avoid impact

Rolled down the window and said if we collided (was not my fault or the pull ahead, it was the kid) Walmart would be working with my insurance company or my lawyer and headed for Jiffy
(naturally Jiffy was 150' from the DT I had left 20 minutes back, brand new store, great staff and great layout)


This thread is not about Walmart or poor customer service. I have had poor service from all kinds of independants, and dealerships. Suggest you go back and read the entire post. Whether it is Walmart or Jiff Lube, leaving up to 20% of used oil of unknown quality should be a concern if your goal is to keep the vehicle for an extended period of time.

 

[4WD]

Oh yeah like how much serviceable is reduced … and blotter tests ?

 

[PimTac]

This idea of 20% of old oil left is malarkey. I've always drained the capacity stated out of my vehicles and filled with the same.

Granted there is some leftover oil but it's not even close to 20%.

 

[Linctex]

Originally Posted by OVERKILL
You are greatly over-thinking this.

. Note that you've removed >80% of those contaminants with the change. Upon fire-up with fresh oil, those contaminants are immediately diluted in the new oil and cease to become relevant.

Then the process repeats as the engine is operated. As long as the lubricant is not operated beyond its ability to perform those tasks, you will not experience sludge or other negative consequences.


This answer gets my vote for the "best-explained"

 

[OVERKILL]

Originally Posted by Talent_Keyhole
The original oil sump contained 25 ppm iron wear. The new mixture within a few minutes contained 5 ppm iron wear. Actually TBN dropped by 10% along with viscosity.

That is not irrelevant. Would you purchase new oil that had 5 ppm wear metals and have viscosity and TBN that did not meet new oil standards, and containing measurable fuel dilution. My guess is that would be NO and you and the average owner would be returning the product and calling customer service to file a complaint or reporting to PQIA. In fact such oil has been reported by them.



I don't see any evidence in the OP that you performed a UOA on both the oil removed from service and the oil that replaced it, sampled immediately after you did a single drain/fill, only that you did a blotter test, so where is this 25ppm coming from? Also, keep in mind that Blackstone says UP TO, the volume of oil left over varies significantly with engine design. Your anecdote about your wife's Aveo points more to the use of a subpar lubricant than the result of a lack of flushing, I've never done a flush on any vehicle I've ever owned and I've never lost an engine, and have always run significantly longer intervals than your wife's car.

Again, we are talking about parts per MILLION, I also see no evidence that you tested TBN. It sounds like you are adding "facts" to your analysis after the fact here to continue to support the narrative that you've spun in the OP. Nobody does flushes, the amount of vehicles on here driven WAY past the mileage on your wife's Aveo, some even using conventional oil changed at longer intervals that have maintained clean internals despite the lack of flushes should speak as to the spurious nature of the assertion that it is necessary or even beneficial. It isn't, it's gross over complication and waste of resources resulting in no tangible benefit. The million mile GMC van, the million mile Ford van, neither of those vehicles received flushes or even had the lubricants changed at conservative intervals.

 

[Linctex]

Originally Posted by Talent_Keyhole

The original oil sump contained 25 ppm iron wear. The new mixture within a few minutes contained 5 ppm iron wear. Actually TBN dropped by 10% along with viscosity.
That is not irrelevant.


Even still, it is a data sample of "1".... perhaps it would be prudent to have a greater sample count.

Run this oil change interval out to a normal mileage, and sample again. Then let's see what you've got.