around 190-200 degrees if you havent' changed the stock themostat to a cooler one. with the cap off, the hottest it can get is somewhere over 212 degrees depending on the antifreeze mixture. plain water at atmospheric pressure boils at 212 degrees at sea level. with antifreeze in the mix and 15 psi pressure cap, the boiling point is elevated to up around 250 degrees or so so it stays a liquid which is what is needed for cooling the motor. make sure you wash the thermometer good after using it as antifreeze is poisonous to people and pets especially. don't leave any spills laying around where a pet can get to it or it can kill them!

 

Thnks for you help!!

 

I suggest you get a mechanical gauge the electric factory gauges suck ***!

I run at 160 with a 160 stat.

In the heat of summer when its in the 90's and the heat index is well over 100 i run 180 and thats idling in stop and go traffic.

But i also have a 3 core,high volume water pump,160 stat.

Try the mechanical gauge i bet its off.