I have been trying doggedly to track down some hard testing data on this very question (see my other posts on this topic). I finally got a hold of an expert on the subject with a ton of real life experience. I spoke to one the principals testers at the Bridgestone Winter Driving School in Steamboat Springs, CO, which my son will be taking their course. Our discussion was not about Bridgestone but about the primary question in my heading. He stated that none of the manufacturers formally test on this, but rather they test on the three parameters we normally see published which involves snow and icy roads (stopping, cornering and acceleration). He confirmed the winter tires today are nothing like the older versions. He is the person who has been testing the tires on dry, icy and snow covered roads for fifteen years. He stated at 45 degrees and lower there is a night and day difference between the capabilities of winter tires and all seasons on dry cold roads. He stated that with this proper tool mounted on the car, I will notice that the vehicle's safety equipment such as ABS and stability control will activate less and when it activates it will remain active for less time. I will not be driving white knuckle. He lived in the Denver metro area so he is well versed in the dilemma many owners face with deciding on tires since we are not in the high mountains (relatively) and get far less snow than a place like Steamboat. Winter tires are also lasting longer than previous versions and I hope to get three or four seasons out of them. Added safety is my primary motivation, but also to save money from any nuisance accidents that would cost much more than any purchase price for snow tires. After this conversation, I am even more convinced and confident that my decision to mount winter tires on my Ascent and my son's 2018 Impreza is the correct one for us.