Im pretty sure my truck (99 24valve) has a 180 stat in it now. what is stock supposed to be? i thought it was 190. i went to the dodge dealer yesterday to get a new one. before i bought it, i asked if it was the 190, and he just said its whatever the computer called for, because it only brought up one. i assumed that would be 190, but as i walked out, i noticed that it said 180. the box said cummins. i returned it, and the parts counter guys seemed confused and insisted it was right. i had tried to get one from an autozone or checker, but i cant find one close that carries them. by the way, checker and autozone both list 190 degree as what they carry.

 

I also have a 99. I replaced with a 180*. Temp gauge reads the same as before. I wonder how accurate the factory gauge is. 10* I wonder if it is a big deal. Fuel mileage seems to be the same also. Oh well another thing for me to worry about on this truck.

 

According to Here the Cummins part # for your truck is 3935811. If that's the one the dealer gave you it should be right. I'm not sure of the temp. rating.

 

that part number matches up to the mopar, except the letters were ac and not aa. it was in a cummins box though. this just helps to confirm my belief that phoenix is filled with idiots. too bad that doesnt specify what the temp should be. it makes sense that mine is a 180 right now, b/c the truck was used on a farm. heavy loads + slow speeds would make sense for a 180. since i only tow on the highway, my engine would benifit from being closer to optimal temperature. i will just find an auto parts store that has one. thank for that link, its got some cool information.

 

Nothin like going to the dealer and getting helped by some guy that only knows how to fetch what the computer says and then give you attitude when you question him. I have read that in the hotter climates guys run the 180* and the colder regions seem to prefer the 190*. I run a 190 since I'm in the latter and its cooler more than its really hot around here.