Back in the 60-70's, we ran 160 thermostats so it wouldn't overheat on hot days. If your radiator is adeqate, 180 is by far better. 160 only helps with an undersized radiator, and then only until there are really hot days. If you need a 160 thermostat, don't cruise on hot night or take trips more than 60 miles. Been there, done that, got the Tshirt.