The numbers are from a VM Motori file I found for the 2.8 motor
Maybe a thermodynamics engineer can understand the BTU input and radiated heat numbers to the coolant and explain what all they mean? It looks like to me the numbers are heat (BTU) input into the coolant at different RPM engine loadings but it does not quintify how the loading is measured or applied.
A little out of my field of expertise...

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

These are the 2 numbers most interesting to me. The thermostat may begin to open at 176F while at most times when I am running the interstate at 75 - 80mph my temp is at 194F based on a fully opened thermostat and the middle position of my temperature gauge. Where the T-stat begins to open and where the operating temperature of the engine is at are 2 completely different temperatures. Still not perfect but better than the 176F everyone thinks we are running.

This assumes a certain ambient temperature. If you live in a warm climate your comment probably applies. You live up here in the Great White North you will find the temperature running at the 176 degree opening temperature, and that only applies if the thermostat is working properly.

You are also in the minority of drivers who state that 95% of their driving is on the highway, where the engine is working steadily. None of the CRD owners I know of have the opportunity to go that fast very often at all, Mario Andretti. You example, therefore, is unlikely to represent the majority of us.

I say - AGAIN - that modern diesel engines run better over 200 degrees Fahrenheit. The anecdotal evidence is simply too strong to ignore, as is the feedback that is posted on LOSTJEEPS.com by my customers.

I believe there is a general misconception that makes many to say that if the thermostat opens at 176, you run your engine at 176 no matter what, which is definitely not true. This can be true only if you're driving in frigid cold, like way below 0 and engine load is not producing enough heat to push the temperature past the thermostat minimum. Or, if it barely produces enough heat to open the thermostat, it will get back to 176-ish right away. First scenario happened to me with good stock thermostat and viscous fan. As soon as I took the viscous and replaced with electric, I had always over 176 (tested with obd2 reader several times, but mostly using the all known, common, very scientific method call "eye-balling" the gauge).

_________________
2005 kj CRD, samco, suncoast tc, provent, Kennedy lift pump, GDE ECO full torque, 2nd gen filter head, 245/70/16 a/t tires, mopar light bar, fumoto oil valve, OEM Skid Plates, ARB Front bumper and HD OME, tru cool LPD47391 40k GVW tranny cooler (stock cooler delete), FF Dynamics e-fan and shroud, rocker arms replaced, HDS2 190F thermostat.

My experience says otherwise. I discovered my stock thermostat was defective on a trip from IL to Florida (pulling a 12' enclosed trailer) and back. My torque app was showing the thermostat opening at 167 and staying there. I recall seeing 172 degrees once in stop and go traffic while pulling the trailer in Florida in mid 70 temps.
I ran the inline for a few months last winter into spring and temps would cycle within a few degrees of the stated temp. I pulled the mechanical fan and that had no effect on temps.
I installed Jeff's thermostat last spring and drove ~6000 miles without a mechanical fan through the summer into fall during my storm chasing season seeing a wide variety of weather conditions and terrain. The temps were always within a couple degrees of 203 in all driving conditions - especially cruising down the highway at speed. I once started to overheat while sitting in traffic with the AC on while in the low 90's. It dropped back down to 203 once I began moving again and getting air through radiator.
My CRD is stock in appearance - stock height and tires, no guards or light blocking grill. Radiator, trans cooler and intercooler are all stock.

My CRD is stock as well except I have my mechanical fan working but run a winter front all year except for summer. I can adjust air flow by opening two flaps.

Recent case in point. Left home for 400mile trip to cabin at 15F and was -15F when I arrived. Only time I stopped was for fuel. This was the only time the gauge dipped below the centermark and it went down to the first line left of center. Any time I was running, the gauge set touching the center line with my OEM t-stat. This is the same position it would run at all times when I had the 195F inline stant in place when I had a non-functioning OEM T-stat. This shows that the engine at load (2300rpms, 80mph, Mario Andretti) with the OEM unit and winter front runs much hotter than 176F.

This tells me that your winter front is effectively reducing the airflow to your radiator to decrease its cooling potential...and/or your cooling system is not as efficient as mine for some reason (restricted airflow through radiator fins for example). I have never seen my temps more then a degree or 2 above opening temperature while cruising on the highway - regardless of ambient temperature.

I believe its how much heat is withdrawn from the engine at various RPMs. As the rpms rise, the flow rate of the coolant increases and so does the heat removed. As you increase flow rate, each additional RPM has less effect than the previous so its a diminishing return. The radiant heat number is how much heat can radiate from the outer surface of the motor at temperature. You would think this would stay the same since the motor should stay about the same temp, but maybe they account for the cooling fan too.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

My Jeep never made it to full temp when I had a bad tstat either.

Also, the radiator covers def work. I've had my jeep overheat climing the 2000ft from Salt Lake to Park City twice when it was like 20F out. thats pretty much full load in 5th gear for 10 minutes, but in normal conditions it stays pegged right at 203.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

That's why I don't like the covers. I'm not against them but I don't like using them, unless it's really cold. Or unless it's below 0 by some decent amount. The cover keeps the intercooler to properly cool the air and just masks the issue of non properly working thermostats or the viscous sucking very cold air... Intake temps also increase, which can be bad if they go up too much. I have never used the grille cover on the ram either, and several times this year were close to 0F in Cleveland. Definitely not as cold as it can get in UT, but lots of people on the ram forum put their grille cover when it's less than 15F, some as high as 30, which I think it's playing with fire. I very much prefer having an e-fan that starts based on coolant temp and not a fan that spins all the time.

_________________
2005 kj CRD, samco, suncoast tc, provent, Kennedy lift pump, GDE ECO full torque, 2nd gen filter head, 245/70/16 a/t tires, mopar light bar, fumoto oil valve, OEM Skid Plates, ARB Front bumper and HD OME, tru cool LPD47391 40k GVW tranny cooler (stock cooler delete), FF Dynamics e-fan and shroud, rocker arms replaced, HDS2 190F thermostat.