Why 2 Different Thermostats Available?

[D'oh999]

A 50 and a 71 Degree Stat. I assume the 50 is Stock, would a 71 (still cool compared to Pressurized Auto) help with anything like Fuel Mileage, Making Oil, Engine Life?

https://www.brownspoint.com/store/pc...l.asp?ID=12425

Is 50 for Hard Working like Pontoon/Barge or 71 for Trolling/idle Motors?