I thought the major design attribute to tire wear was the rubber compound. A
harder rubber will wear longer than a softer compound, but will have less
traction, be it 80 series or 45 series.
Now the more fundamental question: What is the primary purpose/objective of a
tire - to wear long or to provide traction? For me it is the latter. I will
sacrifice the wear mileage anyday for a stickier, better traction, and thus
safer, tire. It is for that reason that I typically do not use all season
tires. To me an all-season tire is like a one-does-all golf club works as a
sand wedge, putter and driver. These are three different functions and a golf
club optimized for a sand trap will probably be a poor putter. Likewise, tires
made for dry conditions will be poor snow tires and snow tires will likely give
less than optimal traction in dry weather. I have a set of summer and a set of
winter tires for each car.