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180º Thermostat ?'s

16K views 44 replies 22 participants last post by  HammerHead 
#1 ·
My '12 is a work vehicle and is turned off and on a lot during the day, sometimes idling for a half hour or so at a time. Would changing over to a 180º thermostat be a good idea?
 
#4 ·
+1 here ^^ A 180 degree T-Stat will open sooner but will not keep the engine running cooler. If youre experiencing overheating issues its important to properly diagnose that and get down to the real issue. Also, a 180 degree T-Stat could cause other issues for you such as the engine running rich (very bad thing) and not having heat right away in the colder weather. I believe the stock T-Stat is 195 or 203 degree anyway so its not significant enough to make itbworth while. IMO the cons outweigh the pros here.
 
#3 ·
id do it. its pretty easy to change so if you notice it starting to really overheat which i personally doubt it will as ive never over heated mine with a 180 just change it out.
 
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#6 ·
X2 ^ I agree. Cooler = safer. My coolant runs at 185 (stock is 203 so 18 degrees is a good difference), oil at 195 and trans at 140 no matter how much I beat on it in 100 degree weather. Overheating is very bad and running lean is very bad. Cooler = richer. Add more air + more timing = lots Hemi power. Certain things that are done for emissions are not good for performance or overall engine life.
 
#7 ·
I disagree. Cooler doesnt always equal safer. You obviously dont want your engine running hot, but unless you have a very high power engine that youre racing, the engine was designed to operate within a certain temp range. The engine oil, transmission fluid, coolant, differential fluid, transfer case, etc. All work at its best when the engine and other components reach that temperature. If you constantly operate at cooler levels you dont allow those fluids to do their jobs.

Im not saying its a good idea to let the engine get too hot, but like I said, its designed to operate within a given temperature range.
 
#8 ·
so 50% say no 50% say yes lol. lets try to help this guy. @jbertulis: what are you trying to accomplish with having a 180 t stat? if its to make the engine run better or something regarding reliability id say leave the stock one in. if its for performance then go for it.
 
#10 ·
If you have a 5.7 hemi, in a 2011 or newer vehicle with MDS you should never be running anything lower than the stock thermostat. The engines do everything possible to increase heat and get up to 190 degrees.
The engineers have done everything possible to get engine, tranny, oil up to temp to reach highest efficiency and reduce wear and tear. Putting in a 180 tstat makes engine work harder and runs a different fuel profile until it gets to temp. Causes more wear and tear on engine and entire drive train. MDS mode won't work until engine gets up to temp, which takes longer with 180 tstat and MDS will switch on/off more often during colder weather (as engine tries to use all 8 cyl to maintain heat) which means worse fuel efficiency. It also effects iDFSO mode, as if engine is cold it won't shut off fuel to engine when you are coasting so you loose fuel economy there as well in colder weather.
In the 2013+ they even have electronic controlled heat exchangers that help bring tranny fluid up to 190 by using heat from the coolant. They also have been routing the coolant close to oil circulation channels to help raise oil temp faster to reduce
wear.
Been covered extensively in Chrysler engineer interviews on other sites (which I can't link to from here.)

180 tstat's in 2011+ 5.7 MDS hemi's is just bad for the truck.
 
#14 ·
i have a 180 tstat in my truck i put it in before my tune. call me crazy but i actually gained mpg and i didnt notice any drop in performance whats so ever. after i installed my tuner i gained another mpg and more power of course. for me i live where it snows during the winter and is hot during the summer. once winter hits im gonna switch back to the 220 tstat. personally i dont think a 40 deg difference in temp would or could cause damage to the engine i mean you could drive across a state and experience that type of temp change.
 
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#16 · (Edited)
If the trans runs better at 190 then why does mine run at 140 from the factory with the factory trans cooler? The higher temps for the motor and trans are for lower emissions and fuel economy. Look at the mods that are done on here to increase air flow, timing and fuel. By your logic these motors are tuned perfect from the factory in every respect and aftermarket mods will only make them worse. Which is far from the case as a few simple bolt on mods easily gets 50 more HP out of these motors with better trans shifts and in some cases better fuel economy. Unless you think the thousands of people on here that mod their truck are part of a vast conspiracy. If Ripp superchargers was able to get a 40%+ increase in HP with a simple bolt on kit and thinks its prudent to put a 180 thermostat in there install kit than it must have merit. These engines are tuned to meet strict EPA standard for emissions and MPG (to achieve high CAFE standards) not for all out performance. Also there are many post with several runs on the dyno. The first dyno pull always has the highest power output when the motor is cold. The subsequent runs show lower and lower power outputs as the engine heats up. This can been seen on the Ripp website where they did 3 dyno pulls in a row on a stock motor and the first (cold) run had the highest power output. Im not making this stuff up, the results are there. See for your self:

http://www.rippmods.com/2009_2011_Stg1_Dodge_Ram_5_7_HEMI_Supercharger_p/0911ram57-sds1.htm
 
#17 ·
I agree that the engine is more efficient when cool, just not too cool, and IMO the trans normal operating temp at 190 is way too high. I even agree that these engines, from factory, are very restricted. What I'm saying is if you do a mod like a thermostat by itself, without any supporting mods, don't expect a very positive outcome in the long run. The engine will try to bring he engine back up to temp and run rich. That's never good.

I have a diablosport tune on mine and love the performance increase. I also put a trans temp gauge in there to monitor the trans. Usually it'll run around 100 degrees unless I'm towing or it's unusually hot out. I plan on doing exhaust, throttle body, etc. So I agree that go don't want anything too hot in your truck and I'm all for modding the truck.

I just consider a thermostat, by itself, in the same category as a CAI (with no supporting mods), a torsion key level kit, turbo timers, etc. Unless you have a high performance engine or mods to support the 180 T-Stat it's a waste of money. So far no one has proven otherwise to change my change my mind.
 
#18 ·
I know see why the engineers post in the other forum and not here.

I never contested that a 180 thermostat in a 2001, 2002, 2003, 2004, 2005,2006,2008,2009 or 2010 might improve performance in a hemi truck. As brondondolon states he thinks he is getting better gas mileage on his 2009 which with their programming may very well be the case.

What I said was on the 2011+ (2011, 2012, 2013,2014 and I would assume 2015) that:

"The engines do everything possible to increase heat and get up to 190 degrees. The engineers have done everything possible to get engine, tranny, oil up to temp to reach highest efficiency and reduce wear and tear. Putting in a 180 tstat makes engine work harder and runs a different fuel profile until it gets to temp."

Which means if you install a modification that keeps engine running cooler than the programming wants, you will constantly be fighting the computers programming and you will have a loss in performance and fuel economy as a result. There is no way around this other than having it run in a hot environment or have something else that generates sufficient heat that the 180 stat is irrelevant anyway.

I never stated that I thought a hotter supercharger would run better times than a cold supercharger. Their tests where on a 2010, not a 2011 so doesn't have the same thermo management programming anyway. And I had already addressed that anyway in my second post I when I said that "So unless you live in 100 heat year round, drive with your foot always to the floor, or have some flame thrower under the hood that keeps engine up around 190+ then its best to stay away from the 180 stats on 2011 and newer models with MDS."
supercharger = flamethrower

I know owe Stan a beer, as he said I would end up be sorry if I tried posting and straighten out the myth on the 180 stat in the newer trucks......and he was right.
 
#19 ·
Well there are a lot of people on here that have mods to 2011+ trucks and are seeing performance gains and mpg gains with a 180 thermo. How could that be?? Including me. I have a 180 thermo, tuner, CAI, headers, and exhaust with mds turned off. My truck is .5 seconds quicker than stock and still gets 16 mpg in city driving with me doing 0 to 100mph runs at every stop sign.

The original poster asked 2 questions. If a 180 would keep this truck cooler when idelling for long periods of time. Yes it will run around 185 instead of 203. And if you read his future mod list includes a tuner. If you are doing mods to increase air and timing then a mod like a cooler thermo that increases fuel helps to complete the package.

Where do you see that the engine is doing everything it can to increase its temp? And would have to fight cooler temps? I did read about trans warmers to get the trans up to operating temp quicker. But that temp must be 140 where my trans runs stock.
 
#20 ·
This is my last post on the matter, as there are always going to be those making the "but my truck is now faster now". The 180 will result in a loss of performance, you might do things that offset that performance loss but only under very rare conditions (flamethrower) is the 180 tstat going to be necessary and not result in a dip in overall performance in the 2011+ due to the PCM.

All the information is out there and can test it yourself you have a friendly tech at the dealership:
A. its in the Gen III Hemi manual under thermal management and I believe its also mentioned under performance profiles in the PCM section.
B. You can visibly see the selection of a "warm up" profile when ram is under temp and hooked up to the computer. And can watch the computer making bad decisions based on external temp and its inability to warm up. Can drive vehicle hard, watch it warm up and select correct performance profile, then fall back to a wrong profile due to low temp. Since tuners can only change whats in the profiles not when profiles are selected they can't tune out this behavior on 2011+ models.
C. You can see it in the thermal management programming (but I already know that the few here that know that are to chicken to poke there heads in on this thread)
D. Find any of the many interviews and discussions and interviews with Chrysler engineers on the subject. There are all over the place.
E. More specifically just find any of the interviews (in print or on video) involving Mike Cairns, Dave Sowers, Fred Diaz and the engineers on the subject.
F: Under http://www.ramtrucks.com/en/guts_and_glory/ there is a video (I can't find, might have been removed to make room for 2014) that has Fred Diaz discussing the thermal management changes since 2011 and how engine/computer now try to maintain higher oil/coolant/transmission temps.
G. Search the forum here, as there are the rare thread were people are quoting the information from the manuals and tech interviews.
 
#21 ·
Thanks for all the replies guys. At the end of the day the most that will be on my truck is an 18" muffler, throttle body, CAI, and maybe a tuner. After reading through this, I'm going to keep the stock t-stat.
 
#23 ·
Install it, you'll be happy you did. No offense to the nay sayers but those who dissagree no nothing about emmisions or performance. If they did they would agree that a 180 tstat would help your engine all around from water, oil, ambient and transmission temps to rubber, plastics, hoses, and gaskets longivity....even aluminum. Think about it, you don't work on a hot aluminum engine because it becomes soft under high heat. Do you think it's cool for your aluminum heads to loose strength under high heat? Would you torque an aluminum head, intake or header bolts while it's hot? If you do you take a very high risk of stripping the bolts. You work on it when it's cool so you can torque them properly without stripping them. If you had an aluminum block you had better be running a 180 or better stat so why wouldn't you want to run one with aluminum heads. The reason why aluminum heads lift under pressure is because of the high heat (cylinder temp), not because of the pressure alone. That's why cast iron heads and blocks are favorite for high boost engines. It won't prevent over heating but it will help your engine stay cooler and perform better. You could not find a notable engine builder anywhere on this planet who would tell you any different. The only ONE reason auto makers use high temp tstats is to burn off illegal emissions and that's it, nothing else. They have no choice but to use them especially in high performance engines that use more fuel. They can build a fast car in todays world but they need high heat to burn off emmissions. In the old muscle car days emmissions did not matter so they ALL used lower tstats depending on the surrounding enviorment. If anything to protect your rubber, plastic, hoses, containers, wires...just about everything under the hood and around the heat use a 180 tstat. At the same time you will increase your engines performance all the way around. That includes wear on every moving and non moving part around the heat. It will NOT affect your computer or cause any codes to pop up and it will not void your warranty. Install it and be cool or don't and be hot, it's your baby.
 
#28 ·
its really easy to do id say the hardest part is getting the thermostat back in because the rubber gasket is such a tight fit. i wouldnt say its hard at all though im just saying its so easy thats the most difficult part. what i did though was i took a very small amount of clean motor oil and lightly coated the contact part of the rubber gasket and applied even pressure all around until it slipped in. dont be alarmed when your tachometer needle doesnt go to the middle of hot and cold thats normal. mine sits at around 1/4th. let us know about your mpg when you find out
 
#30 ·
I had the HemiFever tune with the stock t-stat and eventually ran a 180 as per Sean's recommendation. We're in that time of year now up in the mountains where it's 80 during the day and down to 40's at night. The main difference I've noticed with the switch, other than a slight increase in perceived throttle response, is fuel mileage with MDS off in the warmer weather around 45-55mph. Best I got with the stock stat was 22-22.5 being light on the throttle and coasting down the mountains as much as possible. With the 180 I, very surprisingly, have seen 22.5-23.5 which blew me away. I didn't even know she had it in her! I think the key, as it's already been said, is that I'm running a tune that is calibrated to run with the 180 stat.

All that being said, I am glad I made the switch. I was planning on doing a few trial tanks and then taking it back out. But it's been 1,000+ plus miles and I still haven't considered going back to stock.

Just my 2.5 cents...consider the extra .5 a bonus. ;)
 
#31 ·
-Expensivetoys

I've never been a fan of lowering t-stats on an stock engine unless it really needs it for some reason. Although engineers tend to do things that aren't always necessary, something like cooling and operating temp must be set up that way for a reason.

That being said, would there be any issue with a 190deg t-stat? somewhere in between the 180-203 options. Again, I don't know if there would be any reason on an '11 style truck. A lot of guys SWEAR buy their 180 stats for better performance and better fuel economy...
 
#32 ·
-Expensivetoys

I've never been a fan of lowering t-stats on an stock engine unless it really needs it for some reason. Although engineers tend to do things that aren't always necessary, something like cooling and operating temp must be set up that way for a reason.

That being said, would there be any issue with a 190deg t-stat? somewhere in between the 180-203 options. Again, I don't know if there would be any reason on an '11 style truck. A lot of guys SWEAR buy their 180 stats for better performance and better fuel economy...
I too would like to know if there is a 190 or 192 degree thermostat that will fit in a 2013-2014 5.7 hemi that will still make the computer system act correctly as the engineers designed it to.
 
#35 ·
I was thinking about getting a 180 tstat for my truck but I was wondering how many mods would you need for it to help? I have a CAI, Tunner, 85 mm TB, flowmaster exhaust.
 
#37 ·
ONLY reason a 180* stat is being used is to reduce block temperate, thus helping to reduce knock after installing high flow air filter, exhaust, tuner, etc.
 
#38 ·
Cooler engine cooler cylinder temp less chance of detonation also the computer in theory ( not sure every computer controlled car) reading the cooler cyl temps will not pull out as much timing ='s more power thru the entire power curve. At the same time cooler engine temp will cause a richer fuel mixture and the computer on some again I'm not Sure Every... Will richen the fuel mixture even more trying to get it to operating temp. Which is perfect for bolt on modded trucks adding cold air, exhaust, tuners, throttle body, headers. If your only mod is a cold air your not gonna see much... If you have all the above it'll make quite a difference and also make it run safer with less chance of detonation because it's running fatter. Back in the old mustang days my blown 93 Cobra had a 160 but that old computer was easy to trick that was before tuners came along. Thermostats are super cheap and easy throw one in and butt dyno!! The cool thing now is having a Trinity T1000 and being able to monitor knock and timing and seeing gains or losses.... I highly recommend the T1000 the drivability of my truck alone was worth the price.
 
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