I've been driving with a 160 thermostat for 4 years and the needle sits exactly at 180 at all times in all types of weather and traffic. When I rebuilt the radiator and water pump last summer, I replaced the thermostat as well with another 160. There's no delay in the engine reaching its 180 operating temperature.

I believe it was generally the recommended thermostat when new when used with permanent anti-freeze.

The 160 begins to open at 157- 165 and fully opens at 185.

The 180 begins to open at 175 - 184 and fully opens at 204.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)