If what your asking is have I done a used oil analysis, the answer would be no. Until last night I had not even heard of such a thing. Is this a recomended process I should look into? Please understand that I'm quite new to most of this. I normaly just took my vehicles to the dealer or a quick lube and let them deal with it. The truck I have now is going to have to last me for sometime, so that is why I'm doing all this research.