I think the reason a 180 was recommended is because if you have a heater and drive the car in the winter, it helps keep the inside warmer that's for sure. I always run a 160 in my cars and I only drive them from late March / early April till mid-Oct so I don't need or care about the heater. As long as the engine runs warm enough to burn all the gas in the cylinders, a 160 should be fine. If you change your oil and smell gasoline in the drained oil, then it's time for a hotter thermostat but if that aint happenin' you're good to go.
