[beas62]

Well a 180 degree thermostat has been available from ripp mods since this summer. My stock temps average a little over 200 degrees, so there's the potential of cooling off the engine 20 degrees or so.

Has anybody got any real info or experience on the benefits of reducing the engine temperature on the 3.6L?

I know the theories. Some say that the higher operating temperature is necessary for the engine to meet emissions requirements and get the best gas mileage. But it also seems that lowering the temperature should decrease the threat of knock - allow more timing advance, as well as increased oil life. Folks over at the Jeep and Charger forums are reporting good results, but I haven't heard much here.

 

[cdahl383]

I've had the Jet 180 thermostat in my R/T for about 3.5 years now with no issues. Never had a check engine light come on because of it and my heat is still blazing hot in the winter.

The stock one on the 5.7 is 203, I'm guessing it's the same for the 3.6 but not 100% sure. My car used to run around 205-210. With the 180 thermostat my car runs around 188-193. It doesn't do anything in terms of adding power, it just reduces the effects of losing power due to heatsoak. My car felt much better on hot summer days with the 180 vs the stock 203 thermostat, not as slugglsh off the line, etc.

You do need a tuner though to take full advantage of the new thermostat. You need the tuner to lower the fan settings. I believe the stock ones are 210 LS and 220 HS. I have mine set to 188 LS and 198 HS now. If I set it much lower than that the low speed fan runs too much. At 188 I don't hear it running very much and the car is still running nice and cool.

If you don't use a tuner to adjust the fan settings, the car will cool down to 180 something while you're moving but once you come to a stop the car will most likely creep back up to 205-210 since that's when the fans are set to turn on stock.

I think I paid $30 for the thermostat and it took me about 30 minutes to install. Hardest part was getting the ziploc bag under the thermostat housing to catch the coolant so I could pour it back into the overflow when I was done. You also want to make sure you have the bypass hole facing up at the 12 oclock position. It's a very simple mod that's well worth it.

 

[beas62]

I've had the Jet 180 thermostat in my R/T for about 3.5 years now with no issues. Never had a check engine light come on because of it and my heat is still blazing hot in the winter....
....

Thanks for the detailed insight Carl. While using a lower temp stat on the Hemi is well proven, I think the use of these on the 3.6 is still in its infancy.

One thing about the Pentastar is that the tuning seems sensitive to temperature. In other words, it never quite runs as smoothly when cold as it does once up to full operating temperature. I believe this has to do with making the transition from open loop (preset tables) to closed loop (O2 sensor input) tuning. Perhaps on a completely stock SXT it would make little difference, but on a modded SXT, there's a significant difference between the OL and CL tuning. Since I'm running boost, it's always a little squirrel-y for the first mile or until at 90% operating temp, then smooths out once the CL kicks in.

That said I believe that it'll run at 180F just fine based on paying attention to many cold morning starts. However, I'd love to hear from another 3.6 owner that has done this. If not, I may have to be the guinea pig.

Cheers!

 

[cdahl383]

I see, gotcha. I'm sure there is someone else on here that has a 3.6L with the 180 thermostat. Just need to get them to chime in.

It's pretty easy to swap in and out though if you did have to be the guinea pig. Not a big job or anything if it doesn't seem to benefit you at all. But hopefully someone will give you some solid advice.

 

[beas62]

FYI - I'm running the 180 tstat now in the 3.6L Challenger and no ill effects. I also dropped my fan settings to compensate and now my fans rarely come on during regular driving. My IATs are lower and it seems a little more peppy. Some more 1/4 mile testing or dyno testing may give better info.

 

[cdahl383]

Cool man, glad to hear it's working well for you. What did you set your fan settings to?

I think I used 188 LS and 198 HS. I found that in the summer if I set the LS to 186 or lower they ran quite a bit. Just bumping them up to 188-189 cut down on them kicking on quite a bit, figured those couple degrees weren't worth wearing out the fans prematurely.

I think the stock thermostate is 203 (not 100% sure for the 3.6L). My stock fan settings were 215 and 225 I believe. So the car was realistically running around 210 most of the time according to my datalogs. Now it's running around 190 most of the time. That extra 20 degrees does make a difference, especially on those hot summer days. In the cooler temps not much of a difference.

It's worth it for the $20-30 you spend on the thermostat and the time to change it out.

 

[beas62]

Cool man, glad to hear it's working well for you. What did you set your fan settings to?

I think I used 188 LS and 198 HS. I found that in the summer if I set the LS to 186 or lower they ran quite a bit. Just bumping them up to 188-189 cut down on them kicking on quite a bit, figured those couple degrees weren't worth wearing out the fans prematurely.

I think the stock thermostate is 203 (not 100% sure for the 3.6L). My stock fan settings were 215 and 225 I believe. So the car was realistically running around 210 most of the time according to my datalogs. Now it's running around 190 most of the time. That extra 20 degrees does make a difference, especially on those hot summer days. In the cooler temps not much of a difference.

It's worth it for the $20-30 you spend on the thermostat and the time to change it out.

On my latest Trinity update, it no longer shows LS/HS settings, it just has a single target temperature. I dropped that original temp 20 degrees.

 

[cdahl383]

I see. Yeah that's all you need is a 20 degree drop. Glad it worked out for you!