As Ray H mentioned, the pour points have gone from what, -24 to -44 I believe? I emailed Phillips 66 lubricants; they indicated no formula change; they simply re-ran the pour point tests because they were getting such outstanding numbers in other cold tests (CCS/MRV). The 5w-20 version, if you can find it, would be one of the best cold weather oils out there, short of Point barrow, Alaska! CCS is 3700 cP where as most 5ws are in the 5,000 cP range.