I noticed these tires are about 3lbs lighter than the stock tires. I wonder how much of the range difference may be due to that. The lower the mass in the tire, the less energy required to spin it.
I think I'm going to give the MPSS tires a try for my next set unless I hear some compelling reason not to. So far it doesn't seem like there is only marginal down side if any. I also read in some of the reviews that they are quieter than the AD07/08 tires, so that would be a nice bonus as well. Too bad they don't have them for the fronts, as Michelin is running a sale with $70 off on a set of 4.