I did a little cost benefit analysis and now I'm stuck using Rotella T 15/40. This is my problem. I'm in my early 50's and my truck has around 50K miles on it, and I drive around 20K miles a year. It's going to take me over 20 years to get this truck to 500K miles and Rotella T has done that for trucks featured in the TDR. The stuff is just to cheap and it works and it is sold everywhere. I am going to upgrade to the microglass type filter
I would like to try the synthetic but it is almost 4 times more expensive 

