I have done my last sample with Blackstone. Their ability to get a sample analyzed and out the door is unsat. If you cannot get the results in a reasonable time to make a decision on changing oil, you might as well revert to just changing oil based on mileage alone. ...And to top it off I've been tracking ash content, an extra analysis, and they forgot to do it this last time (and when I asked them, they had tossed the sample). For the present I'm going to use WearCheck. Will let you...
Oil Analysis problems
Oil Analysis problems