I have searched but wasn't able to find the answer and I went all the way through the "Could we have a sticky for common mods? " it is mentioned in there a couple of times and I have seen it in many signatures but I don't know why you are doing it.

I am guessing that you are taking out a cooler thermostat and putting this in to get a better burn on the fuel but I'd like to prove my theory right or wrong. If that is the case what kind of differences are you seeing?

 

That's supposedly the case, but I have a 192 deg in mine, and it runs just fine and gets good mileage (best of 22.1). I wouldn't waste the $$$, personally.

 

its not a waste when your trying to get all you can get with your truck..and IMO you PMR guy's should run a 203...i know on a CAT motor in a big truck run a 210 t-stat...if the motor blows and you have cooler stat in there..they will not warranty it..they have a set temp to run at..you should keep it there.... here is a copy and past from dieselsite
you can see more here
http://www.dieselsite.com/pdffiles/h...nginetemps.pdf

"Question: Why do (should) I want my truck to run warmer?"
[Begin. For your review: The following is unsolicited feedback about the 203 degree PowerStroke thermostat by DieselSite.] While reading your Q&A, your answer touched on some complex interactive relationships familiar to engine designers that can't be reduced to easily understood statements. I offer this differently focused explanation for your consideration.
"Question: Why do (should) I want my truck to run warmer?"
Answer: You should want your engine's oil & water temperatures warmer to
1) reduce piston/ring sliding friction,
2) to complete combustion before the crankshaft has rotated so many degrees which translates into more "area under the curve" of piston pressure pushing the connecting rod down to rotate the crankshaft, and
3) to better purge volatile oil-borne combustion byproducts from its oil supply.
Just as injector nozzle pressures over 30,000 psi have enabled diesel designers to generate higher torque from identical total fuel flows of better atomized fuel presenting more surface area to oxygen which induces earlier combustion completion, so too do higher combustion chamber temperatures also cause slightly earlier combustion completion during the power stroke. Earlier combustion completion results in higher gas pressures earlier in the power stroke which are converted into higher average crankshaft rotating pressure. Gas pressure converted earlier into crankshaft rotating work is not later available as waste heat at the bottom of the power stroke. That contrasts with later combustion completion which fails to convert as much gas pressure into crankshaft rotating energy so more gas energy is still available at the bottom of the stroke as waste heat. That complex relationship is why earlier combustion completion, whether caused by better fuel atomization or by higher combustion chamber temperatures, lowers exhaust gas temperatures while simultaneously increasing crankshaft power output.
Most internal combustion engineering texts estimate roughly 80% of internal engine friction originates from piston & ring sliding friction within cylinder bores. That power absorption curve is directly reduced by increasing oil film temperatures. Reducing internal engine friction reduces fuel consumption required to overcome total internal engine friction at every point along the rpm curve. Therefore it also improves specific output power value along that curve and slightly extends that curve higher at its top due reducing that sliding friction component.This is apparent in slightly lower BSFC (Brake Specific Fuel Consumption) curves caused by higher oil and combustion chamber temperatures. Ford gas racers engine designers tend to target about 210 degrees.
Volatile combustion byproducts which bypass oil and compression rings can condense into crankcase oil. Higher oil temperatures reduce that condensation effect. That translates by higher temperatures oil supplies stabilizing at lower combustion byproduct condensate contamination levels. Crankcase ventilation into incoming air charge stream designs work are better able to reduce combustion blowby condensate oil fouling when engine oils are warmer.
Together these effects produce higher power from earlier combustion completion as compared to later combustion completion, even when excess oxygen insures 100% combustion as is normally true. Higher oil temperatures also reduce fuel consumption due to both this "area under the curve" effect and from lower internal friction at all throttle settings. Finally, warmer engines show slight total net maximum power gains due to these combined separate mechanism's effects because they extend that curve's peak value by simultaneously increasing fuel efficiency and lowering internal friction. Oil self-cleaning does not improve engine efficiency over short periods, but over extended periods lower oil fowling is another clear benefit.


Notice that the attached Navistar 7.3 internal friction curve is NOT linear. Read some of its values to realize how disastrous continuous high rpm operation is for efficiency in this engine series. At 2,800 rpm, it requires fueling 72 horsepower of internal friction before you can obtain the first net horsepower of output! An explanation of it's trade-offs compared to other diesels like the 5.9 Cummins would considerably extend this already long note. Higher nitrous oxide emissions argue against higher temperature thermostats. [But as shown here…]Your higher temperature thermostats directly improve that very expensive internal friction curve.
End
--------------------------------------------------------------------------------------
MANY THANKS TO THE ENGINEER THAT SUPPLIED US WITH THIS TECHNICAL INFORMATION ON HIGHER TEMPERATURE EFFECTS ON THE NAVISTAR 7.3L DIESEL ENGINE. HIS SUBMISSION WAS COMPLETELY UNSOLICITED AND WE APPRECIATE THAT HE TOOK THE TIME TO SHARE HIS FINDINGS ON OUR PRODUCT WITH US. WITHOUT HIS TECHNICAL EXPERTISE ON ENGINE DESIGN, THE BENEFITS OF RUNNING A HIGHER TEMPERATURE THERMOSTAT IN OUR 7.3L ENGINES WOULD NOT HAVE BEEN EXPLAINED TO THIS SIGNIFICANT DEGREE. - Bob Riley

 

by the way..a link to Powerstroke Mods and Maintenance

 

This is a topic that has been written about before and with a lot of strong opinions either way.
One example:
https://www.ford-trucks.com/forums/927229-203-stat.html

 

I know what Bob says, but to date, nobody has any hard proof of gains. Personally, I ain't fixing what isn't broke. I'm running a 192, getting 22+MPG (when I feel like driving like gramps LOL), and making 450 HP on a PMR motor. If going to a 203 improves on that, it can't be by that much.

 

Thanks for the reading material, my head is starting to hurt. I'll have to do a bit more research.

If only I knew how to search for a #. Searching "203" yielded nothing.

 

Here's the one sold by Bob Riley:
http://www.dieselsite.com/index.asp?...ROD&ProdID=186

 

subscribing

 

If where you live you have cold winter weather, I think the 203* is a good investment. Otherwise, probably not so much.

 

IMO, here in MI my truck constantly runs high idle in parking lots and in town in the winter because its not up to temp.
I'm going to try a stat if for no other reason than high miles on my original. I'm not expecting anything major, but am curious if it wouldn't just help me in the winter like when the temp is in the single digits.

 

A hotter stat won't help it warm up any faster (or stay warm at idle), both will simply stay closed until their opening temps. Which really means the 203 stays closed longer, IF you ever even get to 203 in those cold MI winters. My normal running temp (engine oil temp) is between 180-190, and only gets to 193 when I run it hard on the highway.

 

I'm not buying it..

FIrst off someone please enlighten me how warmer oil reduces piston/ring sliding friciton??

Warmer temps=lower viscosity.

Lower viscosity=less lubrication




Oh, and ROn, I know Cat industrial engines thermostats are fully open at 197*. I cant remember the spec for on-highway, ill look it up.

EDIT:just checked. Heavy duty truck begins to open at 190* and should be fully open by 208*
THe industrial engine thermostat, also the standard thermo, begins to open at 180* and fully open by 197*.
Cat says max temp on pressurized cooling system is 210, non pressurized is 200.

 

please do..a CAT teck told us they want to see there motors working around 210*..the 350 CAT the 425 CAT and even the 450 cummins i am driving now will run 180* all day long and the fan never kicks on as long as im empty...once its loaded and im climbing the Mountian's the temp will climb to 210*..at that point the fan kicks on and the temp gauge will drop to about 200*-205* when the fan stops and the temps start to climb again....but what do i know..ive only been watching big rig gauges for 20 years....

EDIT: lol you edited your post..so hotter is better..they want 208*-210* climbing hills..thats where you get the best fuel burn and power witch means better MPG..witch also explains why IH wants 203 in a medium duty truck such as the 444E

 

All I'm going to say is that I don't buy the hype. There's theory behind it, but nothing which can be proven. I personally wouldn't spend the money or time to swap it out, actually I wouldn't have it done if it were free. Truck runs just fine the way it is and nothing leaks. Why go screwing around with that housing so 6 months later you can make a post about how your new sweet billet 'stat housing leaks? No thanks.
I'll also add that a mere 10 degrees change in coolant temp doesn't necessarily equate to 10 degree difference in oil temp. Besides my oil temps are routinely around 200 anyway and vary depending on how hard I'm giving it to it. Why would I want to go hotter than that? We want the oil hot, but there does come a point to where the oil doesn't need any more heat to work as efficiently as possible. Then you get to the point where the excess heats causes things to actually wear more quickly.

So what temperature is that exactly?