I just changed out my fiancee's oil last night in her Regal (3800 V6). Previously I was running Mobil1 10w30. It's been extremely cold here for the past 3 days (0deg F). With the Mobil1 (which only had 2000mi on it - I change her car on a 3 month basis because of the amount of short trips she takes) the car turned over pretty rough, and sounded horrible for the first 30 seconds after startup. The Havoline syn 10w30 on the other hand cranked over much more easily (even though it was colder outside) and the starup noise stopped after about 5 seconds. I plan on sending off a UOA at the next change. I really think this is an excellent oil that has long been a sleeper here on the forums. I noticed similar results (reduction in engine noise both at starup and when at temp) in my 03 Century as well.