Z06 1of38

I keep mine in the fridge.

Lasts even longer in the vegetable crisper.

NmtMev

I should have phrased that better. It "starts" to degrade would have been the correct choice of words. By no means is the oil unusable.

Gearhead Jim

Yes, GM is happy with changing the oil once per year if you don't drive a lot of miles, and the oil in your engine is certainly experiencing more severe conditions than a bottle stored in your closet.

We recently traded our 2009 at 102k miles, and I had oil analysis done for my own amusement at every change. The two viscosity measurements on the report were always well within the specified range, and usually, maybe always, right in the middle.

NmtMev

OP never asked if the oil goes bad. He just asked if it degrades over time. The answer to that has been posted above. The time it takes for oil to actually become unusable. Honestly I really don't have any idea.

Kracka

Every-other year in the Chevy Volt!

I'm still trying to wrap my mind around that...and if I'm comfortable with it or not.

AORoads

As usual, it depends. How long are you going to keep the Volt? (esp. since, at some point, you will be replacing the batteries, and at some point it will be on your nickel)

Kracka

Volt batteries are actually showing zero signs of degradation or failure. There are a few guys north of 250k miles still getting the same battery range as when new. Regardless, they're covered under a 8/100 warranty and I'm sure we'll replace it before that expires. Ours is a 2013 and still getting 45-50 miles of range on a charge (not bad for batteries rated at 38 miles).

Gearhead Jim

An addition to my post #23:

The last oil change on our 2009 was at 95,259 miles on the car and 5,240 miles on the oil. That run included a day of hot lapping with three sessions where the oil temp got above 290' for about 5 minutes each time.

The Mobil 1 5W-30 viscosity was fine, very slightly above the exact middle of the range for the two viscosity specs they test. Wear metals and everything else were normal.

LDB

AORoads PM’d me about this thread. I must confess that I don’t open all that many threads any more, and this one’s title and mouse-over opening sentence hadn’t grabbed my attention enough to open. But now that I've opened the thread, it does seem like some are taking a pretty extreme position. Starting to degrade after a month or two on the shelf, and not recommended for use after 6 months? As one of the respondents pointed out, how can it be ok in the car for a year, exposed to high temp, air, combustion acids and water, etc, and be risky after a few months in a sealed container?

While I confess that I have not seen storage life studies with my own eyes, neither did I ever hear any warning from those who did pay detailed attention to such things that shelf life measured in months was in any way risky. And I’ve seen enough studies of year-old oil that is perfectly ok after being exposed to the above-mentioned rigors of operation that shelf life of a few years in a sealed container seems more credible than the few months mentioned by NmtMev. The enemies are time exposure to heat, oxygen, acids, water, and soot, plus the shearing action of rotating bearings and sliding rings. You have the time element while on the shelf, and if stored in a garage, a small element of heat that I’d really call warmth instead of heat, but none of the others. I don’t know that I’d go all the way to 5 years on the shelf, but I certainly wouldn’t bat an eyelash at a year or two.

iclick

The way I look at it is that if XON thought there was the slightest functional degradation before five years on the shelf they would recommend a shorter expiration period. They have every incentive to make that recommendation as low as possible.

Hoonose

I would not worry about using 'old' oil. I change my oil every year. And I would suspect that a year in the car is just a bit harder on oil than sitting on a shelf.

I haven't heard about many engines here wearing out prematurely, but I've only been on the forum since the C5 days. Am I just missing that?

fnbrowning

Are you saying then, that you consistently used Mobil 1 5W-30 for the entire 100K miles, and you did do HPDEs with the car? What were your OCIs?

If you maintained Mobil 1 5W-30 in the car around that time frame, you did not see high iron numbers with Mobil 1 as other BITOG testers did??

Gearhead Jim

Yes, I used Mobil1 5W-30 for every mile on the car.
Oil pressure at idle and at 3k rpm, both at 180' oil temp, were unchanged in my two checks at 3k miles and ~80k miles.
Oil consumption after initial breakin slowly increased from ~1 qt/18k miles to ~1 qt/10k miles at 100k total miles. Of course, I was actually adding 1/4 to 1/2 qt at a time, not waiting 10k-18k miles for a change.

I typically did a few autocross weekends each year, but the high speed track day a few months before trading was the only time for that.
The autocross weekends didn't produce anything unusual on the oil reports, and to my surprise, neither did the track day when the oil temp got to 293' and stayed there for a while on three different lapping sessions.

The oil changes came whenever it was convenient before a long trip, so some of them were with the OLI still up around 70%, some went down to 30%. An OLI of 40% remaining would typically be around 6k-8k miles on the oil.

My iron numbers never raised any comment from Blackstone, and were typically somewhat less than the "universal averages" that Blackstone listed for other LS3 engines using various brands of oil, and the universal averages typically were with fewer miles on the oil.
During the winter non-driving season (~3 months), I would start the engine every two weeks and let it idle while I exercised all the other systems in the car, that would usually get the oil temp up to 180'. Then I would go up and down our 150 ft driveway a few times. Oil reports done after a winter of that technique, compared to summer-only reports, were basically identical.

Hope this helps.

449er

Lol

NmtMev

I do feel strongly that a synthetic oil will have a longer shelf life then a non synthetic. The 1 to 2 or even 6 months I stated above is where I would put the beginning or starting point of oil degradation. I was not implying that your oil is totally useless @ that point. Not even close. 1 yr old oil is where I would draw the line personally.

The issue is that one guy says this and another guy says that + all the variables involved. There could be no direct answer to the question of how long will it last stored + after the fact how long will it be in the motor.

for example the OP stored his oil for years. Then he went on and ran that oil in the car for a whole year after the fact.... that would be my biggest concern.

I couldnt even begin to tell you how viable that oil would be after the fact. There are so many factors involved in that.

there is no reason for you to stock pile M1, it's on sale like I said all the time. To each there own. I highly recommend to people to send in a baseline sample of the same oil they put in there car, along with a used sample.

If I still worked for _____________ I would totally take one of your guys 1,2,3+ year oils and compare it to a freshly bottled M1. And post the raw ICP and viscosity data rightvhere for you to see... However times have changed and I've moved on from that job.

LDB

Sounds like you are mostly talking about property changes in your highly boosted cars as the oil aged, or variation from batch to batch of Mobil 1, or analytical standards having one year shelf life where shelf life is typically defined very restrictively as time before some small property changes take place in the “zillionth decimal place”. Have you actually seen direct, legitimate shelf life data, meaning, for example, several quarts of oil from the same batch, where the original sealed containers were opened and analyzed at 6 month intervals? If so, can you be more specific about which properties changed by how much over what time span?

I admitted in my post #29 that I have not seen such data with my own eyes, so my skepticism is indirect. I know that others in my company did look at such things, and I would think that I would have heard about it if shelf life was a problem on the short time frame that your posts imply. I agree with your observation that different people can reach different conclusions from the same data, so I’m not trying to get you to agree with my conclusion. I’m simply trying to understand what part of your conclusion is drawn from hard and direct shelf life data, versus softer, indirect and/or general observations that are more subject to interpretation. If the former, I may change my post #29 opinion, while if the latter, we can politely agree to disagree.

NavyBlue2

The petroleum in conventional oil has been in the ground for millions of years, under extreme heat & pressure.
Now this full synthetic oil is supposed be superior to conv oil.
So I can't imagine the engineers of these companies not making full synthetic oil that won't last more than a few years stored in the garage.

Never wondered about how long/old is the oil been sitting around at the dealer, or Jiffy lube, or on the shelf at Walmart...

NmtMev

This is a very specific question, and its a very good question. I'm going to try my best to answer in small sections. The exact question you posted above. I can tell you my answer is partially no and yes at the same time... bit lets just say no for the sake of it to your specific question above, not Mobil1 and not quart sized containers..

if you would like an explanation read below:

The only data I had on M1 was personal data. I never personally tested the same lot number or batch of M1 6 months or a year apart. I never thought to do that, since I never stocked up on the stuff. I was more concerned of what i was getting from batch to batch. That data i did have was pre and post oil use. New batches of M1 that I tested for personal use varied in Vis, wear metals additives and initial base number. But that is to be expected for obvious reasons.I would say that they were well within +/-10% of typical of what XOM stated... that is acceptable when your speaking consumer engine oil. Some were actually right on the money. One batch of M1 I got was way out of spec, specifically referring to initial Viscosity according to M1 guidelines. That was a 1 time occurance. Let's also exclude any customers oil trending data and reflection as well.

I could tell you a little story here. That is somewhere in the realm of your question and could carry some weight. This is for motor oil in general. While at this company (its not Blackstone btw so no one freak out ) On top of our ISO 9001 cert. We were also trying to attempt to get an ISO 17025 accreditation ( highest one you could get for this type of laboratory) we did achieve that. One of the requirements was that we regularly sample and trend a "like" (i.e. engine oil since it made up a bulk of our 800 or so daily samples received from customers) for QC purposes. This QC sample proved to be one of the biggest challenges to overcome. We started off with a 5 gallon pails of 15w40. And thought lets just sample out of that. The goal was to gather long term sustainable data. Same lot numbers, so we started off with 4 containers. Well trend trend trend away on the 1st 5 gallons and we got a great amount of data... Sure enough were running low maybe 1/8 jug left and data starts to skew slightly. Still well within the initial opening 10% range.

Next pail, same lot number same everything.... didn't look exactly the same, but it was close enough...so trend trend trend again. Same thing happened toward the end of the 5 gallons again....

same with #3 barely passing out initial +/-10% range by the end.

By the 4th pail it was pretty clear that the viscosity had dropped off slightly during the initial opening, wear metal additives were lower overall, however initial base number was about the same, and the FTIR results were always a moot point I would say we were burning though 5 gallons every month n a half. So also another moot point was that the oil was transferred to air tight sterile satellite containers on a weekly basis. However that didn't explain why we were getting lower results from initial drum to drum of the same lot number. So that ended up not working for the long term. Too many variables... once again LOL!

The consensus was that we came up with was not clear one. Either the oil is degrading over time, or the oil that we are getting is varying despite the same lot number. The company decided to go with number 1. In the end they decided to also go with using 1 55 gallon drum of the same oil and start trending that...I could not tell you what happened afterwards as I ended up leaving the company for greener pastures.

I still don't know the exact answer as to how fast or how long or at what rate, I have a general idea though. I think I'm just gonna leave it as yes oil does degrade over time with 100s of variables affecting that rate. BEST I could say

LDB

Thanks for taking the time to write that out. Your drum tests are the closest to a clear shelf life test, but as you say, they still leave uncertainty. I can’t rule out your best guess that you were seeing degradation, but I like some other possibilities better. One that I like better is the one your outfit rejected, namely, that there was drum to drum variation even in the same lot number. Once you are talking 55 gallon drums, you are talking a big batch, and if the supplying company blended it in a tank rather than via a good inline blender, then depending on how conscientious they were about mixing in the blend tank, drum to drum variations are easy to believe. And there are other possibilities too.

Depending on the type of analysis, tiny amounts of oxygen or moisture can have disproportional impact, so even if you transfer to air tight containers, there’s significant potential to pick up oxygen or moisture that affect analyses and wouldn’t have been there if successive sealed quarts had been taken off a canning line. That's probably why you said FTIR results were moot, as they are among the worst in that regard.
Transferring containers also has significant potential to mess things up, particularly the metals analyses because they are low to begin with (usually measured in ppm, not %). Since metals are notorious for getting adsorbed on the container walls if the containers are squeaky clean, or desorbed from the container walls if they weren’t squeaky clean, the metals being adsorbed/desorbed from container walls can be significant relative to the low level of metals in the samples themselves.

For now, I think for the reasons in my earlier posts and the uncertainties in yours, I’ll stick with believing a few years on the shelf in a sealed container is ok. But as noted earlier, I can’t rule out your conclusion. The next time I see one of my old lube specialist contacts at a retirement function, I’ll quiz them about it. As I’ve noted in earlier posts, I was not a dedicated, narrow focus, fuels and lubes specialist. I was one of a small number of refinery-wide technical staff who worked on things where you had to understand how it all fit together. As such, I learned a fair amount of detail about pretty much all refining topics, but on any given specific topic, there were always specialists who knew more about that specific topic than I did. Your issue is a good example. While I have reasonably in depth understanding of lube issues, lube shelf life isn’t something that ever came up for me.

NmtMev

You most definately welcome. I agree, consumer oil analysis is a very specialized field. I spent 8 yrs there. The company was one of the first pioneers in oil analysis, specifically what kept them afloat were old navy contracts back in the day like 50 years ago😁. They came up with some great new testing methods in the years gone by. As well as proprietary testing equiptment to further their cause. Large diesel fleets and contracts kept them steaming ahead. Unfortunately the small family run company was bought out by a ginormous french company... and we all know how those things go. (Hence my desire to leave)

I too continue my career in the oil refining business, the closest I get to the laboratory now n days is delivering the samples from my rounds to the little receiving area. I've peaked in there a few times. They use the same brand of machines my old employer used. Same everything almost. There is actually an opening for our lab, I haven't put my bid in yet. Don't know if I wanna go back to that. The money on the process side is extremely lucrative!