From the Amsoil site on Shelf Life
Well, the answer to that question depends on who you ask. Shelf life recommendations for lubricants can vary significantly, from a year to a century, depending on a range of variables. The primary issue is storage environment. Not all motor oils
are stored under ideal conditions. Here is a short list of factors that can influence the shelf life of motor oils.
. Some formulation chemistries and certain additives are more aggressive than others. The nature of the chemistry can affect the shelf life of lubricants.
. Both high heat (greater than 100ºF) and extreme cold (lower than 0ºF) can affect lubricant stability. Decreasing the storage temperature can cause sediment formation and additive separation. The ideal storage temperature should be between 45ºF and 80ºF.
. Water can react with additives in the lubricants to form insoluble materials and shorten the shelf life. Water can also promote microbial growth in lubricants. If water gets into the container through improper handling or condensation, condensation can occur when the storage temperatures fluctuate over a wide temperature range.
. Elements such as iron and copper in the oil can catalyze the lubricant oxidation process and shorten its shelf life. These elements can be introduced to the lubricant by improper handling, storage and use of equipment.
. Frequent agitation of an open lubricant container can incorporate air into the oil. Oxygen can react with lubricants and affect their viscosity and consistency. Agitation also serves to emulsify water into oil and increases the rate of lubricant degradation.
The optimum storage environment for motor oils and other lubricants are as follow.
1. Store lubricants in a cool, clean and dry indoor area.
2. The ideal storage temperature is between 45ºF and 80ºF and at a temperature that does not fluctuate significantly.
3. When storing drums or other large containers outside for extended periods of time, ensure that no dust or moisture enters the container.
4. Grease containers should be stored right side up due to bleeding (fluid separation). Bleeding commonly occurs with grease and is more prominent at higher temperatures.
5. Wipe off the tops and edges of containers before opening to avoid any contamination from improper handling.
6. Always use clean tools. Common signs of improper storage or contamination of a lubricant may include:
• Layering within the fluid
• Formation of solid particles
• Color change or hazy appearance
If any of the above conditions exist, the lubricant may have become contaminated or its shelf life may have been exceeded. In any case it is advised to dispose of the product properly. In some instances a lubricant can be tested to determine its serviceability. If the product’s test results fall within the original specifications, it should be suitable for use.
One more thing to check. You’ll want to validate the product’s performance claims against the current OEM specifications. Equipment design and specification changes over time can make the old product obsolete for new equipment. The current API spec motor oils is SM and for 2007 diesel vehicles it is CJ-4.
Bottom line, there are a lot of variables to consider, but generally, under ideal storage conditions the estimated product shelf life for AMSOIL lubricants can be quite long, with five years being a guideline. Care should be exercised when using lubricants that have been stored for a long time.
I know this concerns motor oil but can be applied to other Amsoil Products. I recommend you get a group together and share for the larger bulk. I buy 110 gallons of HP Injector oil every year, about 150 gallons of Interceptor and currently I am buying a Marine/Diesel Motor oil 55 gallon barrel about every two months.
Also remember Amsoil is not a petrolum based product (it is a pure synthetic base unless you purchase a blend) so it does not react to long term storage issues as does normal oil products.