Charlie D. wrote:
I use Rotella and do oil analysis. Where do I look on my reports that would tell me if their is shearing? Have not had any issues but I did buy Delo recently for my next change.
Charlie, here is a clip of my first switch to 5W40, Rotella T6 full synthetic. This was in 2010. It shows the loss of viscosity. The column for SUS Viscosity @210F on the left was the current sample, the gray column is industry averages, and the 3 columns to the right of that were my previous analysis, each with 15W40. Each of these were approximately 5k mile on the oil. Later I started shortening the oil change interval, eventually down to 3k mile, and that was the longest I could go and keep a reasonable viscosity. You could also easily hear the effect of the lowering viscosity in the engine injectors.
It was still worth it to me to run the T6 and changing sooner, because the cold starts at low temps in high altitude are so much cleaner. But I found that the AR9100 worked even better, even running dino 15W oil.
I don't run enough miles per year to change oil by season, and we live in the temperate climate of So Cal. We only see the cold mountains when we take a trip. I need an oil that does the job everywhere, towing or not.
