Attention: TDR Forum Junkies 
Recently I changed the coolant/anti-freeze in my truck. I also installed a 180 degree thermostat; unfortunately I did not check the t-stat for operation prior to the install - but it seems to be working fine.
The factory temp gauge readings have definitely been lower since the installation of the 180. The gauge on my truck has 3 hash marks in the operating range. Only the center one is numbered and that is 190. I am assuming the first mark is 165 and the last mark within the range is 215. I base my assumption regarding the first mark on several posts that I have read on this web sight that suggested the ISB engine in the Dodge has a most efficient operating temperature of 165 degrees. Also, the 25 degree increment works out well starting from the lowest numbered reading of 140 to the highest numbered reading of 240.
The needle on my gauge pretty much stays at approximately 1/8th of an inch to the right of the lowest mark in the operating range which I have designated as 165. Yesterday for example, I had driven about 9 miles at 65 mph with the air on when I got caught in a traffice jam due to a wreck. I was stuck for about 20 minutes or so. The outside temp was 89 degrees. The trucks temp gauge moved maybe another 1/8th of an inch but then settled back to the orginal mark. I did turn off the ac while I was stuck. When I arrived home, 8 miles farther and 20 minutes later, I popped the hood and check the coolant overflow tank to see how high the level had risen after a few minutes. Much to my surprise the coolant from the radiator was not even going into the overflow tank. I can only assume that the engine did not get hot enough despite my ordeal.
I know from reading the factory service manual that I have, a 190 degree t-stat starts to open at 181 degrees f. and should be fully opened at 203 degrees f. I don't know what the specifications are for the 180 t-stat.
To those of you who have switched to the 180 t-stat, I was wondering if your trucks temp gauge pretty much mirrors what I said above? By the way, I have not towed anything since my t-stat install nor have I driven the truck like I stole it. Maybe if I had, the gauge needle would have moved closer to the 190 mark. Thanks.
The factory temp gauge readings have definitely been lower since the installation of the 180. The gauge on my truck has 3 hash marks in the operating range. Only the center one is numbered and that is 190. I am assuming the first mark is 165 and the last mark within the range is 215. I base my assumption regarding the first mark on several posts that I have read on this web sight that suggested the ISB engine in the Dodge has a most efficient operating temperature of 165 degrees. Also, the 25 degree increment works out well starting from the lowest numbered reading of 140 to the highest numbered reading of 240.
The needle on my gauge pretty much stays at approximately 1/8th of an inch to the right of the lowest mark in the operating range which I have designated as 165. Yesterday for example, I had driven about 9 miles at 65 mph with the air on when I got caught in a traffice jam due to a wreck. I was stuck for about 20 minutes or so. The outside temp was 89 degrees. The trucks temp gauge moved maybe another 1/8th of an inch but then settled back to the orginal mark. I did turn off the ac while I was stuck. When I arrived home, 8 miles farther and 20 minutes later, I popped the hood and check the coolant overflow tank to see how high the level had risen after a few minutes. Much to my surprise the coolant from the radiator was not even going into the overflow tank. I can only assume that the engine did not get hot enough despite my ordeal.
I know from reading the factory service manual that I have, a 190 degree t-stat starts to open at 181 degrees f. and should be fully opened at 203 degrees f. I don't know what the specifications are for the 180 t-stat.
To those of you who have switched to the 180 t-stat, I was wondering if your trucks temp gauge pretty much mirrors what I said above? By the way, I have not towed anything since my t-stat install nor have I driven the truck like I stole it. Maybe if I had, the gauge needle would have moved closer to the 190 mark. Thanks.
