I've got about 300 miles on the Pennzoil syn 5w20 in my Chrysler. From a NVH standpoint, I'm not as impressed with this as I was the PureBase 5w20. I've got start up rattle from my main bearings with the syn 5w20. I didn't have any with the regular 5w20. Wonder if the 200+ ppm of moly vs the ~40 ppm has anything to do with that? Overall, my engine just seemed to be smoother with the regular 5w20.