Originally Posted by shertex

FWIW, here's a note from someone who works at the lab that did my oil analysis, explaning why he would stick to a 1% limit if he were in my shoes:

I would shoot for less than 1% on an automotive engine as the sump capacity is smaller and the potential damage with high soot. If you look at the sample we have been discussing you can notice a common pattern. Your previous sample had a low value of soot and the lead and iron values were much less than this sample of lead and iron. Lead is always from the rod and main bearings and generally lead/tin/copper are the bearing layers. The iron can be several places but it typically will elevate with soot. You are being very proactive with your vehicle maintenance and I just try to help with any advice i can provide with a "fellow gearhead". I would keep with the Delvac 1 as this is my product of choice with all my vehicles, gas and diesel. Keep the soot to less than 1%, (which could be excess idling, lots of local driving, or intake restriction), keep up with Delvac 1 and continue sampling and I see no reason why you can't get 400k plus.