Everything under the hood will thank you. I've run 180F thermostats in my 2 hemis for about 500,000 miles, total. Only thing I've replaced: fluids and spark plugs.

 

I know on other forums people say not to change it because if it was better Chrysler would have put them in from the factory. Well my truck is not staying stock so I want it to perform the best.

 

I think the truck should give better MPG running the higher temp, I did say should not will.
It may also be a Gov. thing for better Burn and Less "BAD" things coming out of the tail pipe. LOL

 

I just towed my 27' boat this past weekend up to Bear Lake which has a lot of mountain grades and for most of the time the truck stayed at 188 degrees, 220's oil temp, and 150's trans temps. Going up the mountains it would get about 215 but as soon as it leveled out the temps would drop back to 186-188.

I like that it keeps the engine substantially cooler. My boat weighs 6600 lbs dry, trailer is 2500 lbs, we had about 80 gallons of fuel in the boat too plus food and coolers and generator. It pulls great for being above or near max tow rating.

 

Water boils at 212F... that's why they put 200 deg thermostats in everything. Moisture in the crankcase is a big bye product of any gas motor, and will cause white milky sludge buildup in areas where oil settles, like your cylinder heads and lifter valley. It's just not a great idea on something you drive all the time.

 

Well my oil temps get over 212 when I'm towing so that will burn off any moisture. When you mix water and antifreeze, the boiling point is higher otherwise you will boil all the water out of your cooling system and kill your engine. Also, having the cooling system pressurized raises the boiling point as well. I know some guys who run water in their cars in the summer but if the radiator cap fails to keep pressure, they are screwed.

 

We used to have Honda gensets destroy themselves in very cold climates, when they made a milkshake of the oil and pushed it past the rings and out the crankcase seals. Did not take very long either. A severe example, I know.

Toyota had major oil sludge problems a few years ago because the engines built so little heat during normal use. Caused lots of warranty work.

 

So is that the thing with these Hemi's they need the 200 degree T-stat for optimal operating efficiency? Anyone with 180 degree T-stat see any negative effects on gas mileage?

 

Scott, can you please PM me? The forum will not allow me to PM you, & I have some questions about the install Thanks.

 

Have been running 180tstat in my 09 Challenger for 70k miles. No issues and keeps the ECT temps down, thus lowering heat soak, thus engine not pulling timing, equals more power. If there was a fuel efficiency hit I did not notice it. There is no milky sludgy oil. A 180tstat will be going in my 14 Ram as soon as I get a tuner.

 

I strongly agree. in order for the auto maker to be within the guide lines for mpg. and pollution they need to run the engines 200 degrees or better along with other specifics. I would recommend oil and filter changes at 3,000 conventional oil and 5,000 with synthetic. But that's me.

 

I know this is an older thread but how do you like the 180 tstat? Any additional feedback? My truck in summer gets to like 222 F on hwy.

I am going to install mine this week. Did you bleed the system? I am alittle concerned with at part of the install.

 

I will tell u this. I read a post here where a guy did his. Used a part number 4128 from Auto Zone. Also can be a 15128 or a 14128 which is a Stant. Well, that is a 64mm diameter t-stat. When I pulled the stock one, it's stamped 63mm. The stock gasket seal will fit the new t-stat, but won't fit in the housing. Unless u force it.
Upon new research, I found another forum post saying u have to shave down 1mm.

But, if u actually go to Stant website, they list as follows :
203* = 48792
190* = 48799
180* = 48798
All 3 come with new gasket which the other one does not. They are apparently the correct 63mm size. Are 2stage type like stock as well. And available at most retailers.

I don't know if the old post I read was on an older year and maybe there was a slight diameter change to the housing at some point. Mine is a 2014. But that's what I can tell u. I wasted time and money on coolant to just be still running stock t-stat still. Bad info....do your research. Lol.