LOL...not sub freezing all year! We do have winter though and I drive my junk. The 160 wouldn’t defrost the windows so I put the 170 in there.
I drive an iron headed 340. Nothing exotic. Since my cooling system WILL keep the engine temp at 170 even on 100 degree days, I use it. My system is pretty efficient, but it could be better.
I also run more compression on pump gas than most guys do, so the cooler engine temps reduce detonation.