Hi,I just serviced my 05 and i replaced the t stat with a new 1 just because.Still had original 190 in it.I installed a new gates 180 from geno's, I didn't know it was a 180 till i drove around and temp wouldn't hit 200 like it did the day b4.It gets in the teens and 20s in winter here and I plug it in. Should I leave the 180 in or replace with a 190 like it came from the factory Or leave 180 in now for summer and put new 190 in for winter?Don't want or need any problems with the motor because of the lower temp t stat.AC did seem a lil colder with that lower t stat could be my imagination though.Any info / help would be great. And yes i used the search and read alot of posts.Thanks.

 

I run a 180 stat too and it's great in the summer but when it gets cold out the truck never gets to operating temp. I usually swap it out with the 190 unit for the winter but I'm thinking about getting a winter-front setup this year instead and seeing how that works. I definitely like like the lower temps while running this thing here lately when it's been in the 90s everyday...

 

And most posts you will find are from guys telling you how that stat will not bring your operating temps down and that it will only take it longer to warm up so what's the point. You and I know better now don't we?!?!?!

 

Definitely runs cooler no doubt about that needle used to sit just a hair off 200f now with the 180 sits quite a bit off 200.I do run the mopar winter front all winter so maybe I will order a new cummins 190f and put that in for winter.I leave for work at 430am so i need the heat cranking especially if its snowing.So 180 will be fine for now especially since its been in the low to high 90s for a few weeks now with high humidity.Thanks DZ.

 

It only takes 5 minutes to swap it out. I didn't even know Genos sold 180 T-stats....

 

Based on some testing I did last winter, the engine runs better and gets better mileage at a higher temp. If anything, I'd look for a 200* thermostat.

In gas and diesel engines, cold air usually makes more power and gets better mileage. But, cooler water temps do not always corrolate with cooler air charge temps. Considering how a diesel operates, injecting cool air into a hot chamber makes sense.

 

According to my butt dyno, my truck runs the same. Mileage has not gone down either. For the piece of mind knowing that my engine is running nice and cool, I plan on keeping this stat in at least through the fall....

 

Regarding diesel engines, the warmer the diesel engine runs, the more efficient it is. As long as you do not have overheating issues, I would run a genuine Cummins 190 thermostat regardless of the ambient air temperature, they are not cheap but work very well.

 

I will be ordering a cummins 190 soon and put it inb4 fall or sooner if i feel like it.

 

I have one though how is 10 degrees really makeing any differance to the good or bad. I have had both and towing heavy my temps hit the same top temp no matter what and instead of seeing 190 after cool down its closer to 180. I've seen no differance in mpgs either way. 10 degrees just don't seem like much

 

a thermostat, by design, only controls the minimum temperature of the engine not the maximum. The maximum temperature is controlled by the cooling system's efficiency. Instead of opening at 190 to allow coolant from the radiator in, it's opening at 180. There can be drawbacks to this if you are towing real heavy. It would open earlier and thus have a longer open duration, but that would not allow the coolant to stay in the radiator long enough to cool off and then temperatures actually climb. For normal daily driving, short trips, highway rolling with low weights, I don't think you will see a difference. But if you really work a truck hard, I would put the factory reccomended thermostat back in it because millions of dollars of research went in to determining 190 to be the correct temp.

 

You WILL see a difference in operating temps. I really don't see why so many of you have a hard time understanding this. With my stock thermostat my temps usually stayed right at the left edge of the center hashmark which is just shy of 200 degrees. Now, after installing the 180 stat, the max temp I have seen even while sitting in bumper to bumper traffic on a nearly 100 degree day is around 180 degrees. Basically, my needle never gets past the "2" on the gauge. To me that is cooler than 1/8"+ over to the right which is where it used to stay.
I have not towed anything since installing it so I cannot comment on that aspect but I would agree that the temps would rise although I believe they would be slightly cooler than with the 190 stat.

The only other thing I will add is this. I have been running cooler stats in my vehicles since I started driving and I have NEVER had a major engine issue, EVER. I'll stick with my cooler stats and my piece of mind......

Out!

 

X2 Zilla I've been doing this in every vehicle I've owned with never an motor issue.
So clutch your saying that when I had a 190 stat in and on a 6% pull with 10k at 104 degrees and I top at 210-215 coolant I'll run cooler quicker then? So now with the 180 I should be running hotter and for longer? So how does that work cause I'm pulling 10k up 6% in 110 degrees and coolant is still 210-215 and still cools down to 180-190 just quick as before.In a hard pull the stat will never close nor do I think you'd want it to. GM's uses a 192 stat and there operating temp is 210(or so has every GM gauge I've owned has said) so hows that work.
On a side note since they have millions of dollars in research you'd think they'd figure a good A/C system like GM uses they've got the coldest air out there.

 

zilla, quadman- I understand what you're saying. The fact is that thermostats do only control minimum temp. I'm merely stating the scientific facts of what each component does, but there are many variables to consider i.e.- how much fuel you're pushing, how much horsepower you are producing, percentage of load, condition of coolant and radiator, engine conditions, ambient conditions, gear ratio, driving habits, etc.

A 180* - 190* thermostat.. won't hurt anything. YOU ARE BOTH RIGHT, but with anything there is a point of extreme use that the other factors that I mentioned would be true. I have a feeling that the cooling systems on our Cummins engines are well over-built (if there is such a thing), but the same can't be applied to a hi-po gasser or all around as a general statement.

I was never saying you guys are lying and I'm sure you do see lower temps, but I was clarifying for people who read it that don't have experience that might assume that a lower temp thermostat will make the truck run cooler which is an inaccurate, not untrue (please note the difference so that you do not take offense), statement. You're maximum temperature is determined by the efficiency of your cooling system as a whole.

And though it may sound contradictory to everything that I have stated in my post above, I generally run cooler thermostats than stock myself.

 

No offense taken by the theories you are putting forth. The fact remains that my truck runs cooler all the time now since putting the 180 degree thermostat in. It was 102 degrees here today and still my needle never moved off the "2". I like that....