The new tire coming along is essentially the r7 same compound as the sm7 slightly different tread configuration no idea of there are any other appreciable differences.
If you believe that the sm7.5 is going to help anyone with tire costs I have some beautiful property to sell you in a very nice swamp in Florida.
i mean if its just moving the SM7 to the R7 mold as suspected, then it should be slightly faster, like slightly, and probably wear slightly, slightly better. the main cost of the dotted line versus full rain groove is the tires wont be as good in the wet/marginal conditions. they will hold the tread more steady, so hopefully give us a bit more wear, and they put more rubber on the road. also means it will spread the heat out over more rubber.
as long as it doesn't cost more, its a win. if it costs more, then its probably not.
either way, not much is changing. the naming convention ".5" tells us its likely a short term solution, and SMAC is looking for more from hoosier for the *