Haulin_in_Dixie

Smoothest thermostat I have had yet, engine runs cooler no hot spikes on hills, just a tad slower to warm up, but never has gone over the middle of the gage, stays right where it is supposed to.

cummins number 3967195 it is 180 degrees.

BigBlue

Hmm. Might have to give it a shot. Thanks haulin.

matthopp

I will be changing my coolant soon and from the advice on these forums, i will probably change the thermostat as well. Your part number is a little different than what i found on the dodge parts spreadsheat, p/n 3937171. I found this p/n on reliablegoods.com for $16, supposed to be a decent place to get original cummins parts. Anyone ever ordered from here? I would think your 3967195 thermostat would fit my truck.

Also, still debating on the type of antifreeze: Valvoline Zerex G-05 or the Fleetgaurd 50/50 mix. Any suggestions would be appreciated.

Haulin_in_Dixie

Yes it is a different part number and will fit your truck. I speced it out from the ISB275 CPL2080. It is the smoothest thermostat I have had yet, no surge at first warm up and so far it has not risen above the half way mark on the gage at any time. It does not go up and down on temperature reading. It is a tad slower to warm up than the oem. Probably any of them are ok, but I have had bad luck with thermostats and have probably bought 8 or 10 of them. One case me my engine. I looked at two or three of them before getting this one. Sound ****? A thermostat cose me $15,000 and four months of work.