Advantages of using lower temp thermostat?

[DieselSJ]

Sorry, didn't seem to sound like I was on a tangent. And it seems like people seem to think a 160 t-stat will make a difference in how your engine "runs" when it won't really make any difference at all, more or less just the temp that it operates at.

Actually it will make a performance difference. There is a reason why we run the racer at 195-210. Regardless of the tune, the engine always made more power at that temp than it did at lower temps.

But I disagree with you about the oil. I'm not sure how a 40 degree coolant temp change translates into oil temp difference but I seriously doubt it's enough to hurt anything. I haven't found that running oil coolers cause sludge build up or any other negative effects on the oil and I'm sure an oil cooler cools the oil more than engine coolant does. Right? :dunno:

Running an oil cooler still lets the oil get hot - it just cools it back down. Keeping the engine cold doesn't allow the oil to heat up properly. Did you know there is an optimum temp for oil? And that temp is a lot hotter than you might think.

 

[Milford Cubicle II]

So an engine with coolant temp of 160 is cold? Lol, hardly. And until I see a dynograph I don't believe that ANY t-stat will make a meaningful power difference.

And what good is an oil cooler if it "still lets the oil get hot"? :huh:

 

[DieselSJ]

So an engine with coolant temp of 160 is cold? Lol, hardly. And until I see a dynograph I don't believe that ANY t-stat will make a meaningful power difference.

And what good is an oil cooler if it "still lets the oil get hot"? :huh:

I can see you know very little about actual automotive theory or have much real-life experience with performance vehicles. I'll leave you to your own little "out there" world.

 

[carves]

Define "low"

Probably pointless ....
As my personal interpretation of "low" for my vehicle and how I use it .... and your "racing" definition of "low" ... will no doubt be quite different ......

Its probably more important that you note my post was all about the advantage getting a stable "lower" temp utilising a different thermostat ... more so than just chasing a "low" temp.

There is absolutely NOTHING wrong with that temp.

I know .... but so many think that the sky will fall and the world will end if its not running at 210' .... and 220'-240' is acceptable ....

195' is in the lower parameters of whats considered "normal" for an XJ .... and in the higher parameters, of what I consider suitable, to allow for boil over issues if a component fails whilst driving ....

Water boils at 212' ... and at 16psi (if the cap is correct) it boils at 260'
50/50 boils at 220' ... and at 16psi (if the cap is correct) it boils at 270'

But even a well maintained cooling system can have a component failure and pressure loss ......

..... and if/when it occurs at 210'/220' with a true 16psi cap fitted ............... BINGO .... :explosion
.... instead of just a fast climb displayed on the gauge from less than boiling to boiling.

Thats why I'm content with it as it is - sitting on a steady 195' - all year round .... for the time being ...

Why are people so afraid to let these things run at 195-210? Heat makes power, boys!

Actually it will make a performance difference. There is a reason why we run the racer at 195-210. Regardless of the tune, the engine always made more power at that temp than it did at lower temps.

Dont think there would be many worried about a 195' temp ... but probably the fact that so many XJs apparently have overheating issues going by the number of internet posts on the web causes a few stray thoughts.

Maybe even the admittance by chrysler about the cooling system inadequacies has something to do with it ???

ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the complaint.
Abnormal loads on the cooling system such as the following may be the cause:​

PROLONGED IDLE,
VERY HIGH AMBIENT TEMPERATURE,
SLIGHT TAIL WIND AT IDLE, SLOW TRAFFIC,
TRAFFIC JAMS,
HIGH SPEED OR STEEP GRADES.​

... and the list of the so-called "abnormals" .... doesnt even cover 4x4 or trailer towing .... ​

So I guess if chrysler expects an XJ to overheat in what lots of us would class as "normal" conditions ..... we should as well.​

Heat also reduces service life / destroys ...... electric/electronic components, oil, engine mounts, bushes and plastics ..... yada yada yada ......

So its all a trade off depending on a particular vehicles use, set up ..... and whether its backyard ... or trackside maintenance ...

Me ... Im quite happy to maybe, chew up a smidgin more fuel or lose a coupla horse power .... if it means I have a cooling system that isnt operating at its max capacity constantly.

... especially since I'm getting 20mpg+ .... and considering Im running a dirty big ol dinosaur 6cyl & auto tranny pushing 2 gearboxes and 2 diffs in a vehicle with all the wind resistance characteristics of a shipping container .... and it goes where/does what I demand of it ...... at a constant 195'.

Again, if you need to run a 160 tstat to stay "cool", then you have something else wrong. Fix the problem and let it run at 195.

Gotta agree with this ... as it echoes my comment about, way low thermostat temp settings, being a bandaid fix.

The thermostat sets the minimum operating temp.

Then its primarily the responsibility of the the radiator and airflow to maintain that temp in all conditions.

If the running temp has large fluctuations, especially hot ones .... from the temp designated by the chosen thermostat - then the cooling system is of an inadequate design for the vehicles use ... or its broke ...