Thermostat OEM Honda or OEM Nissan

Your temp gauge is reading low because your mechanic is not using an OEM Honda thermostat. An OEM thermostat is designed specifically for your engine and the car will warm up quickly and the temp gauge will sit at the 50 yard line in any weather.

The Honda thermostat opened probably 50% more than the aftermarket, so lesson learned there.

When I stuck the key in the ignition, the temp needle pegged the far end of the hot zone. AAA towed it to the Nissan dealer and they put a thermostat it in for $50 or something and it worked perfectly after that.