Quote:
Originally Posted by gatorfast
You can still measure if wear metals are decreasing over a specified period  If you used one oil and changed every 8k miles and then switch to another oil and change every 4k miles you can still see a trend and compare.
i.e. if you change TWS at 8k miles with a lead reading of 15ppm, switch to M1 and change every 4k miles with each lead reading being 2ppm I would say its obvious that wear metals decreased.
I know you are very academic about everything but you may be over thinking this one. |
This is not an "academic" concern. It is fundamental to observation of data and conclusions about such - so I don't really agree. With a simultaneous oil brand/weight switch and mileage interval switch one can't separate which caused the change.
Now, given the specifics of your hypothetical case, which is totally different from that to which I originally replied to, I do agree seeing those changes one could make a reasonable conclusion that the oil was making a difference.