I can only give you an impression, nothing scientific, since I have too many variables that aren't the same in my comparison of the Sottozeros to the stock 18" Michelins. For my type of driving, I'd really only notice a loss of range if it were 20 miles or more, plus I went up one size to 245/45-18 with the Sottozero 3s that I put on my car. My impression is that there is a slight loss of range with the Sottozeros, but that it's less than 20 miles. That said, the Sottozeros were generally driven in much colder weather than the stock tires, and running the heater in the car hurts the range much more than the A/C. I might have a better idea of any range difference when I put the Sottozeros back on for this winter.