I have a 1996 Volvo 855R currently running Rotella Tripple T 15W40 engine oil. Previously I ran Amsoil 5W40 Euro because we had it on our shelves. My boss is a huge fan of Ams and has been for 20+ years. We service many vehicle that use Ams 5-25k service intervals on their engine oil as well. When I used the 5W40 Ams in my car it would tick during start-up and initial 5 seconds. This is something that ive seen with Ams and am wondering if their 0-10w is so thin that it drops out of the top end? I switched over to the Rotella and have not had this concern. Rotella obviously has a much higher centistoke especially during the colder mornings here in colorado so I would think that it will stick better. Alldata calls for 15w40 if above 0 degrees F, and pretty much 5W40-10W30 depending on the climate. My question is what are the thoughts of Rotella in this application, which oil may be better for this engine, or would the Rotella 5W40 full syn be a better option. I do know that since Rotella first came to the market it was almost considered a syn due to their hydro-crack tech of the molecules to size them down. It also performs very well through heat cycles and is great with turbocharged applications. Thoughts, comments, etc??? Thanks!