A test I'd like to see ....
Take two used oil samples at the same time from the crankcase after say 5000 miles. Test one sample ASAP and record the data ....Allow the other used oil sample to sit at room temp for several months and then test the second sample at the same lab. I'd be willing to bet this second sample shows significantly more degradation.
Once moisture, fuel and acidic combustion byproducts are introduced into your oil, it will continue to degrade - EVEN IF THE ENGINE IS NOT RUNNING. Of course the rate of these reactions is heat dependent and does occur much more rapidly at elevated temps. However, processes like oxidation and acid formation also occur at ambient temps, as do reactions between oil additives and the small amount of unburned fuel that gets into the crankcase.
One of the primary reason why Amsoil has an explicit one year time limit on drain intervals in gas engines, and six months in diesel engines, is to account for the fact these degradation mechanisms occur even at ambient temps ....
Ted
I have a question. My Dad and I are testing the Trasko bypass/full flow filter on his Tacoma. It is 1995 with the 2.7L 4Cyl. DO you have enough UOA of your truck for use to compare the UOA once we hit 10,000 miles? I just want to establish some extended drain averages for this engine. The black stone averages will not figure very well I am sure!
