Those hell-bent on a lower T-stat should read this

[Bandit]

I know for a fact that the SRT Engineers have stated on record to owners that you should never swap out for a lower thermostat.

Someone at the SoCal M&G (could possibly have been Ralph Gilles himself) also said the same thing about ALL LX's, not limited to SRT's.

Here is another post confirming this, AND a technical explanaition as to why: Click the link thingy (http://www.srt8oc.com/forums/showthread.php?t=984)

I'm not telling anyone what to do, simply empowering them with the factual information neccessary to form a concienscous decision.

[Rev.Hammer]

This is all new information to me from a local Mopar Performance Shop that is building a 6.4 Hemi stroker engine. First, tight bearing oil clearances, hence-the 0W-40 oil, secondly, this engine has very short length aluminum pistons (skirt to piston top), hence the 203*thermostat:thirdly, the top piston ring end gap is only .007 and the extra heat expands the rings for a better seal, lastly, a MDS system isn't possible because of the cam profile and lobe centerline design. I'm not convinced that a cooler temp thermostat is needed as the stock PCM looks at this temp in the performance mode and because of the stock design of this engine. Now when the parameters of the PCM are modified, all the other changes would add to the performance. DCX has at least two modified PCMs but they aren't being released. Why? Maybe the Warranty Factor? Hacking into the brains of any new PCMs is much more difficult now than older designs. However this can be done. I'm not convinced yet on all the jumping into performance modifications until they are tested fully. All this information was made available to me at the track last Sat. 4/8. The way this engine pulls stock there is a lot of performance not tapped into. Also some of the Performance Tuners on the 5.7 Hemi have had some software problems and aren't perfected totally yet. So be patient and let the Vendors experiment first. MHO Gene

Courtesy of SRT8JEEP of SRT8oc .com


Has anyone here reported or seen any effects of blow-by?

[Zog]

I hear a can of worms opening!:popcorn:

[Rev.Hammer]

No worms from me, all I care about is veracity!

[HotRodK]

I like V E L O C I T Y myself.

[mikeyb]

I bet they are running the 200 degree thermostat for emission reasons.


MikeyB

[Bandit]

No, the reasons are stated in that article.

[MAGNUM8R]

C'mon and Stir it Up!!!

[boggart]

I don't think the SRT guys would tell you not to change thermostats if they were only running them for emissions. They only have to pass emissions tests before they sell it, if it would run better with a lower t-stat, safely, they would be all over telling you to put a lower t-stat in it.

Seems pretty clear to me... Change the stat if you want to change the engine later on and then change the stat back when you pay for the new engine so you don't have to keep doing that.

[mikeyb]

I have a hard time believing 20 degrees makes that big of a difference in the metallurgy.

MikeyB

[createdbyone]

i hate when we argue over these things. Thank god we dont have an LX race car...we couldnt even agree what octane to put in it lol . I think we should just all kinda do what we want to do. I personelly run a 180 thermo, wont tell anyone else without warning becuase we really dont know if it is good or not. I think experimentation is what we need on these forums.
Whenver someone tries something, i will never scold them. Experimentation is what brought us the MDS light, 25 cent fan mod, the overly complex no code fan mod, the fuse 17 cabin switch, shaving of the moldings, etc

I say to each there own and we just have fun watching everyone try new things

None of this post was sad in anger. Im a very easy going person and I typed this with a smile

So..."Cant we all just get along?"

[boggart]

I don't think anyone is arguing really. But i do think there will be people who put in a lower temp tstat and trash their engine because of it. DCX engineers have told us so, why should we not believe them. The only question will be will the customer a.) do the right thing and own up and accept responsiblity, or will they b.) change the tstat out before taking it in to the shop and claim warranty repair, or c.) take option B and still badmouth DC for having inferior engines even though they were told time and time again not do do the mod.

If everyone chooses A. and accepts their own fate and agrees to claim responsiblity then I think everyone who wants to run a little better should do it. I would just hate to see DC get black eyes over thrashed engines a couple of years down the line (thats at least how long I think it would be before anyone sees any real impact)

[createdbyone]

oh i wont have a warrenty in a few weeks, so i dont think i should be in this discussion

[Bandit]

I agree with MagnumSXT. I am not posting any of this to get a rise out of anyone, or to shake my finger at them. Just to let all those who may be unaware that there ARE warnings about this directly from those that designed and built the cars.

I think experimentation is the key to unlocking real performance from any car, but when you're told directly that this one thing can and WILL cause serious, permanent damage to your engine... it is a warning that should be heeded.

[DawsonMagnum]

I don't think anyone is arguing really. But i do think there will be people who put in a lower temp tstat and trash their engine because of it. DCX engineers have told us so, why should we not believe them.

We need to be careful with hyperbole. Unless I missed something, DCX engineers have NOT told us that putting in a lower temp t-stat will "trash" an engine. I have seen comments from the SRT people saying that they aren't necessary and that they might cause faster engine wear, but not that they will kill the motor:

4. Running temps: Adam said that this is a big misconception. The SRTs do not run hot. They are running at the temp which provides the most amount of power without decreasing engine wear. He said he wished the actual temp gauge was changed so the normal running temp. was in the middle or lower rather than the upper end to avoid this unwarranted concern. He said using a 180/190 tstat is not needed.
...
DISCLAIMER: These comments are merely my interpretation of what Adam and I discussed and by no means discounts anyone else's opinion or current mod. choices.

And the intimations made in the post (and it is a post, not an "article") on srt8oc.com are NOT from DCX. They are from "a local Mopar Performance Shop". I'm not saying the info isn't TRUE, but it is not, as they say, from the horse's mouth. And even if what they're saying is all 100% true, do we have any evidence that it will damage the engine? I admittedly don't have much knowledge of blow-by, so forgive me if there is obvious precedence on its detrimental effects on engine logevity.

And last, but not least, is that all the "official" comments we've (or at least that I've seen) been seeing have been from SRT people about SRT engines, not RT engines. It stands to reason that the same things may apply, but we don't know this.

[bipto]

LOL, man - now you're really gonna think I'm a bitch! :lol:

I must admit that based on all the conflicting info being presented about lower tstat use, I'm still kinda on the fence on this issue (still running stock temp), but I see nothing in that post that would lead me to believe that running 20* cooler part time (in the absence of a lowered fan-on threshold) is going to cause catastrophic engine failure. At worst, I see potential endurance / longevity issues, but IMO these are risks that we run to a varying degree with virtually any mod. I certainly do not mean to imply that that Adam Forte and the other engineers don't know what they are talking about, but IMO they may be speaking with an overly-cautionary bias here.

I do agree whole-heartedly, however, with the notion of accepting responsibility for the mods we make. If I know or even strongly suspect that I broke somthing, I'm not going to try to get the DCX / the dealership to foot the bill. If I felt that the risks were not somehow worthwhile, I'd still be running bone stock.

This was not intended as a flame. I do appreciate the info and hearing the different perspectives. I just don't believe that the facts surrounding this issue have been completely sorted out, and until they are, we can agree to disagree, right..? :wink:

[DawsonMagnum]

LOL, man - now you're really gonna think I'm a bitch! :lol:

Nah...not a bitch. Or at least a well-spoken bitch, if so. :)


Very well put, I think.

[createdbyone]

im still waiting for the guy to pull off his supercharger and try to get dodge pay for the engine rebuild lol

[Husker]

I agree with Bipto, if I do something that fries my motor, it's my issue!! But I also can't see how 20 degrees between friends will cause issues. I guess we shall see for those of us who run the cooler tstats..

[Cam]

Sorry, not going for it. The thermal expansion of the compression ring is not going to change enough.

[Cabo Mag]

As I have already posted this, a reminder that when talked to the Jet Chip folks regarding their Stage 2 chip, they emphatically told me NOT to put a cooler thermostat in this engine.....

[jhs914]

Sorry, not going for it. The thermal expansion of the compression ring is not going to change enough.

Makes sense to me. That combustion chamber is mighty hot no matter what thermostat you run. However, I am not an automotive engineer (but I do play one on the internethttp://www.lxforums.com/board/images/icons/icon7.gif).

Too cool of a thermostat can cause cylinder wear. I don't know who this guy is, but he makes the case here that 175*-180* is the optimum temp:

http://www.carnut.com/ramblin/_cool3.html

http://www.carnut.com/ramblin/img212.gif

[aries4life]

I'm with CAM, I'm not buying this. Dropping the engine temp by 20 degrees ON AVERAGE, all the time with modified enginge high-fan on, would only cause a couple of ten-thousandths (.0000) of compression on the parts in question. This would cause too much blow by if the engine operated normally on the bleeding EDGE of too much blow by. Seems like it would affect emissions more than anything. <--my opinion. Then again, I didn't treat the parts in question either - DCX did. They know more than I. They did test the motor extensively. You know they experimented with coolant temperature. The real question is with their agenda. We need to hear it from someone that KNOWS. Are they trying to protect the end user from premature engine failure (less than 200,000 miles)? Or are they trying to protect themselves (less than 70,000 miles)? Are they just trying to protect their engineering reputation (we designed it to be perfect the way it is)? Or are we just over-anal-yzing something simple? :grin:

[Displaced Hokie]

I suspect it's got to do with emissions and that the ECU is programmed to work with this temp. If your engine never gets to to the proper temp (what the ECU is looking for), then that could get you into trouble. Maybe she runs a bit rich which leads to washdown of the cylinders. I don't know. This engine is obviously tight, so there could be some wild things that come into play.

On a newer engine like this, I also don't see much advantage in lowering the coolant temp of the engine. Sometimes I think people are hanging on to the old way of tricking the GM EFI. Run a lower thermostat and make the engine run on the "cold loop" and thus richer. It's almost "shadetree-ish".... *as I duck the sure to be thrown tomatoes*

Hokie

[aries4life]

it's hardly "shade-tree".. though the ease of a thermostat swap is. Our cars are obviously more powerful when just below the 190 degree mark. It can shave a few tenths off of a quarter mile run. I remember something about 170 degrees being too cold and 185 being the sweet spot for power but I can't remember all of the details. Somebody feel free to chime in on the dynamics of open loop vs closed loop operation on the 5.7/6.1L. I believe 170 is the minimum operating temperature for closed loop operation. We are keeping the engine's computer in complete control of the game (if we operated too long below the minimum we would get CEL). We're referring to the actual increase in wear and possible increase of blow by associated with lower engine operating temperatures.

[maneval69]

ONE MORE TIME from the LX MANUAL
FUEL CORRECTION or ADAPTIVE MEMORIES

DESCRIPTION

In Open Loop, the PCM changes pulse width without feedback from the O2 Sensors. Once the engine warms up to approximately 30 to 35° F, the PCM goes into closed loop Short Term Correction and utilizes feedback from the O2 Sensors. Closed loop Long Term Adaptive Memory is maintained above 170° to 190° F unless the PCM senses wide open throttle. At that time the PCM returns to Open Loop operation.



14 - 96 FUEL INJECTION LX

OPERATION

Short Term

The first fuel correction program that begins functioning is the short term fuel correction. This system corrects fuel delivery in direct proportion to the readings from the Upstream O2 Sensor.

The PCM monitors the air/fuel ratio by using the input voltage from the O2 Sensor. When the voltage reaches its preset high or low limit, the PCM begins to add or remove fuel until the sensor reaches its switch point. The short term corrections then begin.

The PCM makes a series of quick changes in the injector pulse-width until the O2 Sensor reaches its opposite preset limit or switch point. The process then repeats itself in the opposite direction.

Short term fuel correction will keep increasing or decreasing injector pulse-width based upon the upstream O2 Sensor input. The maximum range of authority for short term memory is 25% (+/-) of base pulse-width. Short term is violated and is lost when ignition is turned OFF.

Long Term

The second fuel correction program is the long term adaptive memory. In order to maintain correct emission throughout all operating ranges of the engine, a cell structure based on engine rpm and load (MAP) is used. Ther number of cells varies upon the driving conditions. Two cells are used only during idle, based upon TPS and Park/Neutral switch inputs. There may be two other cells used for deceleration, based on TPS, engine rpm, and vehicle speed. The other twelve cells represent a manifold pressure and an rpm range. Six of the cells are high rpm and the other six are low rpm. Each of these cells has a specific MAP voltage range Typical Adaptive Memory Fuel Cells

As the engine enters one of these cells the PCM looks at the amount of short term correction being used. Because the goal is to keep short term at 0 (O2 Sensor switching at 0.5 volt), long term will update in the same direction as short term correction was moving to bring the short term back to 0. Once short term is back at 0, this long term correction factor is stored in memory.

The values stored in long term adaptive memory are used for all operating conditions, including open loop and cold starting. However, the updating of the long term memory occurs after the engine has exceeded approximately 170°- 190° F, with fuel control in closed loop and two minutes of engine run time. This is done to prevent any transitional temperature or start-up compensations from corrupting long term fuel correction. Long term adaptive memory can change the pulse-width by as much as 25%, which means it can correct for all of short term. It is possible to have a problem that would drive long term to 25% and short term to another 25% for a total change of 50% away from base pulse-width calculation.

SO a 180 Tstat should be in the center normal operating temperature.

As far as SRT8jeep's post, I don't see anything there except speculation, which is fine. But it hardly make for any kind of support against a cooler T-stat. He merely said he is not sure if there is a benefit.

I know from my dyno testing that the A/F is leaner when the engine temp is lower (which is better for power - to a point). And my best 1/4 time was starting at 185 degrees.

[Bandit]

Yeah. I agree.

What the hell would the designer of the car, and the SRT engineers know about our cars?

It's all nonsense. Tomorrow I'm off to install a 120 degree thermo, NOS, and some "WOO-WOO" whistler tips on my car. (jussst kidding!)

This will be my last post on the subject. I for one am going to listen to those who have the engineering degrees, and actually built the cars we're discussing. I think in the long run my engine will thank me.

I will be interested in seeing the long term effects of those who are using the lower t-stats though. A few weeks or months of using it really shows nothing... 4 or 5 years from now... well, that's a different story.

[aries4life]

I missed the part where a DCX engineer that worked on the HEMI development team posted on the issue. Can someone point it out to me? Is "SRT8Jeep" the one in question?

Edit: re-read the 'SRT8Jeep' post: 'Gene' "isn't convinced" that a lower temp thermostat is "necessary". Are there any words from the aforementioned techs that discourage the use of a thermostat below the, factory set, 203 degrees? Are there reasons?

[Bandit]

I know for a fact that the SRT Engineers have stated on record to owners that you should never swap out for a lower thermostat.

Someone at the SoCal M&G (could possibly have been Ralph Gilles himself) also said the same thing about ALL LX's, not limited to SRT's.



From my initial post.

The top paragraph was referencing an SRT group chat on chargerforums. SRT has also told ME directly the exact same thing.

[Bandit]

Ok, THAT was my last post on the subject ^^

LOL

[bipto]

Yeah. I agree.

What the hell would the designer of the car, and the SRT engineers know about our cars?

It's all nonsense. Tomorrow I'm off to install a 120 degree thermo, NOS, and some "WOO-WOO" whistler tips on my car. (jussst kidding!)

This will be my last post on the subject. I for one am going to listen to those who have the engineering degrees, and actually built the cars we're discussing. I think in the long run my engine will thank me.

I will be interested in seeing the long term effects of those who are using the lower t-stats though. A few weeks or months of using it really shows nothing... 4 or 5 years from now... well, that's a different story.
LOL, 06MNSRT8 - now you're starting to sound grumpy like me! :lol:

Your post was good info with the best of intentions, and that's what we're all about here, right? We may not all agree with it, but you put it out there - in the end it will help each us make up our minds on this mod one way or the other. :thumbs_u:

[aries4life]

Don't we have guys that work for SRT pop in our forums? Could we ask one of them directly if they do? I REALLY want to know the answers :)

[aries4life]

lol y'all post too fast.


Just to clarify: I re-read some of my own stuff and it almost sounds like sarcasm. NOT MEANT TO BE! I just want some solid - from the horse's mouth - information. This topic has peaked my interest. After thinking about it for a little bit, it seems to me a 180-185 degree therm would be best for overall performance (taking emissions out of the equasion).

[Bandit]

LOL, 06MNSRT8 - now you're starting to sound grumpy like me! :lol:

Your post was good info with the best of intentions, and that's what we're all about here, right? We may not all agree with it, but you put it out there - in the end it will help each us make up our minds on this mod one way or the other. :thumbs_u:

Ain't it the truth.. perhaps because I stubbed my toe before opening this thread. might have made me cranky LOL

I just wanted to share information, for better or worse.

[DriveATransam]

the problem with the 203 degree thermo is that it can run way hotter. ive seen 215 degrees driving around town. that seems pretty hot and i wasnt even beating on it that hard. what happens in the dead of summer when im rolling first and second to redline in traffic?

extra head heat to seal the rings? comeon! are you kidding me. face it...they dont want you to modify the motor because then you will start doing anything to it and come warranty time THEY dont want to be the ones to be blamed. "well an srt8 engineer told me to put a 160 degree thermo in. i didnt know it was gonna wash the walls with gas". they are protecting their ass, duh. i would tell someone the same thing if i had to fix something they screwed up on after i had it running perfect.

[maneval69]

Yeah. I agree.

What the hell would the designer of the car, and the SRT engineers know about our cars?

It's all nonsense. Tomorrow I'm off to install a 120 degree thermo, NOS, and some "WOO-WOO" whistler tips on my car. (jussst kidding!)

This will be my last post on the subject. I for one am going to listen to those who have the engineering degrees, and actually built the cars we're discussing. I think in the long run my engine will thank me.

I will be interested in seeing the long term effects of those who are using the lower t-stats though. A few weeks or months of using it really shows nothing... 4 or 5 years from now... well, that's a different story.
How old are you?
You seem awful defensive.

One thing an SRT8 engineer would know is a lower Tstat will increase emissions and he would get into trouble if he said using one was a good idea.

Who is the SRT8 engineer?

Try some research instead of listening to me or the SRT8 fairy.

[maneval69]

Why would wear increase with a 20 degree reduction of engine temperature?
The only thing I could think of is contamination in the oil caused by a minuscule increase in blow by gases. But the PVC should take care of that.

[kudasai]

well, first things first. why dont we see how much it would expand? does anyone know the circumfrence of a piston? we can apply this formula

EXPANSION/CONTRACTION = LENGTH IN INCHES x DELTA T x .0000129

and subtract, lets say what we get from 180, from 210 and see the difference. i can see blowby from rings, but what i would look for on engine wear would be piston...uhh, slap?

so lets see some numbers....

[maneval69]

I had an LS1 camera that had piston slap issues because the piston skirts were too short. It sounded like a knock.
If you don’t have piston slap at start-up in the winter you won't have it as a result of a 20 degree reduction in coolant temp.

As far as the thermal expansion,
Don't forget that the block expands also. Now cast iron has a coefficient of thermal expansion of 0.0000061. Which is half that of aluminum. So you would use the difference between the two to find out what happens to the gap.

so you math guys check this and correct.
We had a 3.92" bore, 3.92”x0.0000061=0.0000239" per degree, x 20 degrees F=.000478”. This is what the cylinder bore contracts with a 20 degree reduction.
The piston, 3.92"x0.0000129=.00005056" per degree, x 20 degrees F = .001011" contraction
Now we subtract the bore shrink from the piston shrink and you get the reduction in piston to cylinder wall gap caused by a 20 degree reduction in temperature. And that reduction is 0.00533"

Now the other thing we have to account for is the actual affect of Coolant temperature on the piston and the cylinder. I would think that the cylinder temp would be reduced more than the piston temp because the coolant makes no contact with the piston. There for the change could not be as big as the above calculation.

Besides if the above calculation is right the when the car starts at 80 degrees you gap would be increased by 0.059” which would cause some serious problems. So I fear that the calculations I used are erroneous.

[maneval69]

OK.
AS far as engine temps and power increases.
I had a 190 tstat but I did not jump the cars fans to run them, I only used an external fan blowing on the front of the car.

Each pair of runs was run back to back. The only time between them was to get the car back in third gear and down to 2000 rpm.




run 10-external fan on –Superchips 91 tune -started at 190 deg.
run 11-external fan on –Superchips 91 tune not sure but I estimate 205-210 deg.
10 minute brake with the fan on for 5 minutes (just estimates)


run 12-external fan off- Superchips 91 tune -started at 185
run 13-external fan off- Superchips 91 tune -not sure of the temp at start but it finished at 225.
15 minute brake to uninstall the 91 tune and got a tour of the shop (the fan was turned back on before the tour)


run 14-external fan on- stock tune - started at 180
run 15-external fan on- stock tune – not sure but I estimate 195-200

Run 10-11 (http://www.chargerforums.com/forums/attachment.php?attachmentid=5552&d=1143087512)

Run 12-13 (http://www.chargerforums.com/forums/attachment.php?attachmentid=5554&d=1143087534)

Run 14-15 (http://www.chargerforums.com/forums/attachment.php?attachmentid=5555&d=1143087547)

It looks to me like the A/F was richer on every second run and that the power was better on the first runs. This is close to proof that cooler engine temps increases power out put.
Also notice that I got the best run after returning to the stock tune. The car was coolest then but I also have my doubts if the 91 tune adjustments are instantly removed. I think it may need some closed loop time to adjust it out.



(http://www.chargerforums.com/forums/attachment.php?attachmentid=5555&d=1143087547)

[Shelby]

If you want to directly compare stock to SC 91 tune the SC 91should be run with 91 octane fuel and the stock with 89. That is difficult to do back to back. It does seem that stock should run worse with 91 than 89 but the dyno runs seem to show them nearly identical. Strange.

We need to see what the great MOFO finds on these subjects.

[maneval69]

If you want to directly compare stock to SC 91 tune the SC 91should be run with 91 octane fuel and the stock with 89. That is difficult to do back to back. It does seem that stock should run worse with 91 than 89 but the dyno runs seem to show them nearly identical. Strange.

We need to see what the great MOFO finds on these subjects.
Why,
I would want to know the difference between stock tune and SC tune. If the stock tune and 91gas has better out put than the stock tune and 87, why would you want to give the SC tuner credit for that?

[Beast]

My problem with this info is that it doesn't jive with i/4 mile times. Lower temps equal lower times. As the car heats up times are not as good. Can someone explain the termo stats need to be 200s when 185 gives better times?

[DriveATransam]

warranty.

[maneval69]

My problem with this info is that it doesn't jive with i/4 mile times. Lower temps equal lower times. As the car heats up times are not as good. Can someone explain the termo stats need to be 200s when 185 gives better times?

Higher temps = lower Emissions

[bradkaye]

I must admit that based on all the conflicting info being presented about lower tstat use, I'm still kinda on the fence on this issue (still running stock temp), but I see nothing in that post that would lead me to believe that running 20* cooler part time (in the absence of a lowered fan-on threshold) is going to cause catastrophic engine failure. At worst, I see potential endurance / longevity issues, but IMO these are risks that we run to a varying degree with virtually any mod. I certainly do not mean to imply that that Adam Forte and the other engineers don't know what they are talking about, but IMO they may be speaking with an overly-cautionary bias here.

The 'part time' statement is what strikes a note with me. I live in Atlanta, and last month I was already running temps in the 2-teens with around town driving. That thermostat is wide open at that point and the engine is running well above 203.

I intend on installing at least a fan mod and probably a lower thermostat, knowing full well if I'm cruising on the hot Atlanta highways with the hot Atlanta heat, with the fans in their normal mode, I'll always be in excess of 203 anyways.

When I restart the car after already seeing temps in the 215's while driving, my Scanguage tells me I have heatsink taking the coolant at the point of the sensor in excess of 230 degrees. Just think of how high the spots of temperature in the top end of the engine are! Can that be good for the longevity of the engine?

I want my 180 thermostat and fan mod to allow me to improve performance for WOT blasts when I feel frisky, but more importantly to help bring the engine to somewhere in the 180's before I shut her down instead of the 220 it'll be if I stick with the stock setup.

I know for a fact that the SRT Engineers have stated on record to owners that you should never swap out for a lower thermostat.

Someone at the SoCal M&G (could possibly have been Ralph Gilles himself) also said the same thing about ALL LX's, not limited to SRT's.

I'm not telling anyone what to do, simply empowering them with the factual information neccessary to form a concienscous decision.
What record? What engineer? SOMEONE at the MEET & GREET said what?!? Some guy at a bar told me he was Jesus... that don't make it so.

Sorry if I'm skeptical about supposed fact that has no actual, documented references. I understand this was a misguided a attempt to inform and protect our members, but statements like that are hearsay, so don't be offended if people don't take it as the friggin written word. The guy you reference is merely referencing what someone at a speed shop told him. Hardly the word straight from the SRT engineers' mouth.

These forums are a wonderful trade of information, and so far, the dynos and time-slips, (THE written word, in these parts) say that more power is to be had at lower engine temperatures, but not engine temperatures so low that contaminants aren't going to be flashed from the oil which could cause longevity problems, or that are going to throw our computers into some limpy mode.

Believe me, I want to drive my car for the long haul, and if well documented FACT comes up that says "sustained driving at temperatures below 203 degrees will harm your Hemi 5.7 and 6.1's" from an actual DCX engineer with an actual NAME, then the LAST thing I'd do is install a lower thermostat.

Until then, I'm going to take steps so my heads don't melt off my car in the 100+ degree, 98%+ humidity summers we have down here.

[done]

When I restart the car after already seeing temps in the 215's while driving, my Scanguage tells me I have heatsink taking the coolant at the point of the sensor in excess of 230 degrees. Just think of how high the spots of temperature in the top end of the engine are! Can that be good for the longevity of the engine?



The company that designed the car to run at those temps is also the same company that warrants the car for 70K miles. Why are they wrong and why are you right?