Hey guys, lets Focus on Staying on the original posters Subject Question.

 

A Machinery Lubrication informative read on the range of possible results of mixing lubricants. Managing the Risk of Mixing Lubricating Oils

 

Thanks for all of the informative links and opinions. I'm deducting that it "might" be OK to use it up, but isn't worth the risk of the unknown, especially with the chemistry involved with modern synthetics. Darn it, I hate wasting the oil. Especially being as expensive as it is, but it doesn't seem worth the risk to avoid the waste. Maybe going for the sales wasn't really saving money after all.

For the record, the way the oil was stored after opening is re-capping and set on a shelf in my garage. I live in a particularly dry climate so moisture is probably not an issue, with regard to contamination via humidity.

I guess it'll have to go to the recycle yard.

 

Use it in lawn & garden equipment.

 

I would just make sure they have the same API ratings, If you want to be careful.

 

Late entry but better late than never. I tend to use the same brand oil, but have mixed viscosities, brands on occasion. Have mixed syn and Dino in lawn equipment. Everything still running fine. On the wife's Explorer, I accidentally put in one quart of tranny fluid on a 10k oil change, same brand, both full syn, and vehicle ran fine. As for the moisture, unless your oil never gets over 212 F, it will remain. Again, never a concern for me. Note that I am particular about my vehicle maintenance but also feel the marketing tries to scare you to never alter anything the manufacturer states. Only concern would be an additive reacting with another additive, but I also feel this would be more applicable to machinery (transmission) lubrication vs engine oil. I have been involved in machinery reliability most of my career and know enough about oil to be dangerous but would not consider myself a lubrication expert.