This weekend on Car Talk, we heard from Avital, presently of San Francisco. (You can hear the call right here.)
Her ex-boyfriend, a mechanic, insists she should demand bottled motor oil whenever she goes in for an oil change. His logic? The oil separates as it sits.
Could he know something that the rest of us don't?
Tom and Ray thought his premise was boooo-gus. Motor oil's job is to hold debris in suspension, after all. And additives are chemically bonded to the oil, right?
But, then again, who knows?
So, we're posting the question right here. Have you ever seen motor oil separate? Do you think the additives drop out? Tell us what you think.
I work in the oil import business. You know, 850,000 to 1,000,000 barrel crude oil tankers that haul crude oil around the world in 100,000 barrel tanks in their holds. I have a job with a survey company testing the crude oil before the crude is unloaded to insure that the water in the “blended” mix has not separated during transit.
Crude oil has a percentage of allowable suspended water in the “blend”. However, once the water separates it has to either be “re blended” or drained off, a very significant added expense to the crude hauler because the crude hauler is contractually obligated to deliver a specific “blend” of crude oil, not just a load of crude oil to a specific terminal. Crude oil tankers actually “blend” the crude oil during transit to prevent separation of the crude and the suspended water. The crude oil is blended between tanks to insure a homogeneous “blend”.
Another division of the company I work for tests bulk tanks (you know, the big white tanks all over the place, like all the tanks in Chelsea and South Boston that you see from I-95 as you speed past them)to insure that the oil has not separated. Still another division tests oil in bulk underground storage (at “quickie lube” shops) all over the country to insure that the oil has not separated.
So, to put it bluntly, oil in the storage tanks has suspended water in the “blend”. Once the water separates, it has to either be “re blended” or drained off. If the water isn’t “re blended” and gets into the engine, the engine is history.
While Tom and Ray seemed never to have heard of this (perhaps unfounded) belief that drum oil is inferior to bottled oil, I know that it dates back to the early days of true service stations. My dad grew up in Philadelphia and worked at such as station as a kid. He tells me that some customers preferred to have their crank cases topped off with canned oil because this allowed them to inspect the product and know exactly what they were paying for. They could confirm from the can that the oil had an API rating and was in fact the grade and viscosity they wanted for their engines. When buying drum oil, on the other hand, the customer had to take the attendant at his word. According to dad, drum oil was, in fact, a cheaper grade back then.
He also told me about the practice of selling “drip oil.” After filling a customer’s engine from a can, the attendant would leave the almost empty can to drip into a glass bottle or other portable container. A few drips from each can would add up over the course of a day, and customers who weren’t particular about what kind of oil they were using could buy the drip-oil at a much cheaper price (this was especially common for people who had older engines that burned a lot of oil, or, I suppose, cheapskates like Tommy).
I enjoyed hearing Avital’s call because it made me remember dad’s story. Unfortunately, when I called him up to confirm the details, it reminded him that I had never repaid the $50 bucks he lent me a couple of months ago! Oh well, it was still a fun conversation, and I still probably won’t get around to paying him the $50 bucks for a few more months.
My question is what would prevent bottled oil from separating just as bulk oil would? Or is it the fact that you can shake a bottle of oil like a bottle of Gatorade to get all the flavor from the bottom of the bottle? I work in the automotive industry where we use bulk oil and I have never seen any problems with using it for the last 13 years. I would have to disagree with this gentleman’s statement even though I can see how he would get this impression. One of those automotive myths it seems to me.
“bottled” oil has to be filled from the bulk. If the station/oil change place is honest, it should be the same stuff, and just as pure. The oil you put into your crank case is not the same as bulk crude which includes water, salt, and whatever. Lubricating oil is refined, distilled, additivized, etc. before it can be used as a lube oil.
A labeled drum of “X” brand having the same properties should contain the same material as a bottle or can of “X”. Granted - drums can be easily refilled with a cheaper product… but… so can bottles.
The use of bulk oil from a reputable place wouldn’t bother me.
Your answer is correct. But the analysis would be by gas chromatography. Gas chromatography separates the oil into its individual (several hundred to 100) components and quantifies the amounts of each.thousand)
Your pronounciation is not so good – ask a chemist --Mass Spectrometry [spec-trom-et-ry] (analyzes the mass spectrum of single molecules better than mixtures}.
Joel Leventhal, Denver, Ph.D. Organic geochemistry
This forum has managed to capture regulars from the fields of mechanical engineering, quality engineering, electronics engineering, automotive technologies, racing, tires, a humblingly knowledgeble tranny expert, and even some physicists.
An organic chemist is a welcome partner. We’ve had countless questions in the past that could have used your expertise.
Also welcome Joel! In my dealings with lubrication issues, my clients, ususally large manufacturers buy all their lube oil in bulk; this may be the same oil that’s used in your cart or truck. I teach a course in lubricant handling and storage, and contamination is the biggest source of lube oil problems, not additive separation.
A fast lube place will stock several standard oils for their lube special and the filling hose will measure out the right amount. The additives in the will stay in suspension, but of course, poor housekeping may allow dirt and water to get into the bulk tank.
Do I use bulk oil? No, since I decide what weight and brand of oil I want, and that is never available from the bulk tank.
CRUDE oil is shipped internationally with 0.5% BS&W, that is bottom sediment and water. That’s the internationally accepted way since it is too expensive to get all the water out. During the refinig process all these impurities get removed, and the final product (gasoline, lube oil, etc.) bear no resemblance to the original feed.
Countries that ship bulk lube oil base stock for blending will try to have it as clean as possible, but the blender needs to clean it up further(centrifuge, filter, etc) before formulating the final product before bottling.
Generally you want bottled oil, not bulk. Not that the oil is any different, but too many quick change places and even some independent mechanics and dealers, buy cheap bulk oil and use that same oil for all the cars that come in, no matter what the car's manufacturer recommends. You want to be sure that you get the right oil and the oil you are paying for. Yea, once knew a guy who did just that.
My thought are that it doesn’t make a bum fugle difference, the average car last long enough that the body is dead and your just plain sick of the thing, so many things have broken and quit, there no freekin heater or A/C and it’s shakes you to death as all the rims are curb bent, who want a car to last any longer. (well except for Ray) My point is, in most cases the car last plenty long enough, with what ever oil you use, bottle or drum. So why worry? Eric in Asheville NC
I think the ex deserves an old-fashioned Tom & Ray dope slap. No way the oil itself separates.
That being said, I might be concerned about other contaminants in the large barrel settling to the bottom- e.g. rust from the barrel itself, junk falling in when the barrel is tapped, etc. But the likelihood of these types of problems is minimal, IMHO.
Eric, in Ashille NC the body of a car may be the first thiung to go, but in many parts of North Amerca it is a lot less humid and the bodies are the last to go. In the West and West Coast there are many engine rebuilding shops, almost absent in the East.
Good lubricationg practices ensure that the engine will last as long as the bodies in these areas. Most failed engines had lubrication or overheating problems.
A basic knowledge of lubrication can save the average car owner a great deal.
NYBo; that is my main concern with sloppy lubricant handling by those jiffy lube places. I’m sure the oil in bulk arrives clean but what happens after that is strictly a function of good housekeeping.
Bottled oil? How uncanny! Imagine if we substituted bottle for can in our everyday conversation. Once you let the Genie out of the can… Prince Albert wouldn’t be involved in telephone humor. We would have to call the corner store and ask him if he has Planter’s nuts. There is just no cure for some problems.
The ex is wrong. First off, yes the bulk container may become contaminated with water if being filled during rain or snow, but that will be floating on the top. And the “pick-up” is a few inches off of the bottom of the tank. So if youare really concerned, only have your oil changed the day after their supply is delivered (giving time for oil/water separation).
If you go to a chain that has the oil company name (Valvoline, Quaker State, etc) and get their bulk oil, it will be the same name brand as is in the bottle. Also, since most people get the bulk, it gets used more often and therefore will be “fresher” than the bottled. For the most part, these places want you to be happy and to return in 3-4000 miles (which is its’ own discussion)
The ex probably worked in a place with very sloppy housekeeping, hence the warning. He is wrong on the base stock and additives seperating.
The life of motor oil is VERY long; it does not not spoil like milk! “Freshness” is not an issue here. My concern is poor housekeepinmg with oil contamination, and the kids in these places putting whatever hose is handy in your engine. If my Toyota dealer uses bulk oil I am not concerned. This dealer has an impeccably clean shop and well trained staff.
I worked for 4)four days at a oil distributor in the summer of 06, I left because I didn’t like the job. anyway on the 3rd morning I helped load some trucks. tanker- single axel. some with 7) seven compartments. 500 gallon,700 gallon, and maybe one 1000 gallons. for a delivery to a new car dealer the order called for synthetic blend, you know. a mix. Well heres what we did, I crawled up to the top of the truck and opened one of the doors to 500 gallon tanks, then poured in 6 or 8 quarts of full synthetic CASTROL, then we added several gallons of our house brand real oil.same weight, I will never buy an oil change from any dealer , I think bottled is at least better. so I go to the store and buy it of the shelf. now I’m sure you guys have heard of this before but thought I’d write anyways
I think you’ve hit on the big reason to me - making sure you’re getting the correct oil. Kind of like when they bring the can/bottle to the table at the restaurant and open it in front of you…