How long does oil keep on the shelf

[45Auto]

Originally Posted by hotrodz

I had a couple of gallon jugs of Mobil 1 10W40 that I used for a Z06 Corvette. Sold the car so they sat for probably 6 years or so. They were sealed, when I picked them off my shelf they were about 3/4 full and had turned a real dark amber color and smelled like cosmolene. Apparently synthetic base stock will break down over time. I think dino oils probably not. Just my O2.

I’ve called Mobile Oil before with same question, first they asked me the date code on the bottle, then she told me she wouldn’t advise me using it! She stated, if I recall, after 3-4 years the additives start to break down and no guarantee that oil is going to provide the engine protection you need!

[RM Art]

I still have the oil can metal top puncture pour spout, metal solid funnel and metal spiral/adjustable extension funnel.

Regarding age of oil - IMO any oil that stays in a well sealed container will outlast any person currently on earth!

[dbircky]

Originally Posted by Shell Man

I worked for Pennzoil for over 30 years. Nothing to worry about on your 10w-30. Use it.

I left shortly after the Texaco settlement.

[kelownawine]

Generally only turbine oils have a shelf life and some synthetic greases.

[Florida Panhandler]

Actually, all I remember were the oil Bottles with the long snouts that sat out in the weather all year long ready to jump to the needs of the automotive public.

[JRI]

Originally Posted by Old-Biscuit

Exactly ^^^^

Remember the Oil Can rack out at the pumps when service station were 'service stations' ....they sat out there day after day, month after month, year after year in metal cans

Have to disagree. I worked in a few gas stations in my teen years during the 1960's and that oil was restocked on a frequent basis. May have looked like it just sat there but it was not the same can.

[D Stucker]

IF you like the generator and want it to keep running a long time, switch to Rotella t6 ot Mobile 1, use heaver heavier weight oil for air cooled gen sets.

[Winemaker2]

Originally Posted by JRI

Have to disagree. I worked in a few gas stations in my teen years during the 1960's and that oil was restocked on a frequent basis. May have looked like it just sat there but it was not the same can.

No doubt it was restocked but were they date coded so you could be sure to use old first when restocking?

[jcussen]

Used to make supply run to Midway Island in the 90's. The transportation dept there were still using drums of oil brought over there in WW2!

[Langeloro]

Originally Posted by Edd505

I don't think there is a shelf life, I wouldn't think twice about using it.

Since it’s an older generator, it’s recommended to use 5w30.

[Latschco]

Originally Posted by rbdaves

I have an Onan Microlite 4000 GenSet in my 1997 Trek and want to change the oil. I have several 1 qt bottles of Pennzoil 10W-30 that has been on my shelf since mid 2018. I wonder if these bottles of Pennzoil may no longer be useable. The seals on these bottles have never been broken. Can I use them or should I go buy new from a parts store?

Even if they were open they are fine.

[Kraken]

The only thing I have ever heard on the issue, is that the viscosity additive molecules might not go from long chain, to short chain, and back and forth indefinitely. That would be if it's stored where there is wide temperature swings for a very long period, and maybe that's not a factor any more or maybe never was.
Kinda like the viscosity additives get fatigued.

[david2385]

Oil has a spec. that it has to meet. Every engine has a recommended oil weight and spec. to use in that engine. If you use your old oil I would make sure it matches the engine spec. I do know the additives in oil will go bad over time.

For the price of oil why risk it. Go buy new oil. Use the old oil in a chain saw as bar oil.

Someone said synthetic oil was different. Synthetic oil still uses base oil. It is processed to a more refined spec.

[NeilV]

Originally Posted by twinboat

I remember the glass bottles of oil and I am in my late 60s.

It was recycled oil and cheaper then the cardboard cans of new oil.

The cardboard cans had metal tops that the piercing funnel was used on.

We still had some Glass Bottles of Quaker State new in the glass bottles when I lived in Massachusetts. Some called them the War Bottles since they started packaging motor oil, transmission fluid and gear lube in the glass bottles again during WWII to conserve metal and cans for the war effort. My dad was born in 1906 and had a lot of them in the garage going back to when he was working his way through high school after WWI. I liked the way the ones with the flexible goose neck spout on the cap poured better than any of the piercing nozzles for the metal cans. Some had brand labels on the inner seal or glued to the bottles while some of the Quaker State to save paper had the brand, weight and grade cast into the glass bottle.

Biggest issue with old oil can be dependent on the additives and how prone they are to settling or separating. Not really a big issue if we are only talking about a few years or so. Some may not even notice since it may stay as sludge stuck to the bottom of the plastic bottle and not come out even if you upend the bottled for hours and let it drip. Automatic Transmission Fluid with a lot of Friction Modifiers can be more prone to separation or settling than motor oil. With grease it can be a bigger issue as the pressure additives can separate from the oil and turn gritty. I have a can of Teflon Grease I have saved for those that don't believe it can happen since it separated and now has a layer similar to hard plastic in the tub that's pretty obvious. I believe that tub sat on the back of the shelf for 10 or more years in order to get that way.

2 or 3 years though should not be a problem and if your dealing with an oil with a lot of modifiers consider shaking it up to get them redistributed before pouring them in and then be sure to run the engine to at least full operating temperature driving a few miles circulating the oil to better keep them in suspension.