180 Degree Thermostat Question

[OUR01GT]

I have purchased a 180 degree thermostat to put in my 2001 GT, OEM as you know calls for a 195. IF I do this swap I would also program my fan to turn on at 180 degrees. Is this truly a good ide to swap the thermostat and change the fan turn on tempature? Thanks in advance.

 

[RandyStinchcomb]

well you dont really want the fans to come on at the sametime the thermo is opening up. I'd say have the fans come on at @ 190* to 200*

 

[todd4566]

well you dont really want the fans to come on at the sametime the thermo is opening up. I'd say have the fans come on at @ 190* to 200*

I believe the stock setting for the fans is 220*. A 180 t-stat with the fans coming on around 200* works well for me.

 

[OUR01GT]

With my SCT programmer you only have a choice of 160*, 180*. or stock. Any suggestions?

 

[DBMSTNG]

go with the 180*

and yes, it's a good idea. i've done it myself.

 

[rjstaaf]

Here is some info on cooler thermostats that you should really consider. There is a reason Ford chose the temperature they did for the thermostat. On a mostly stock motor I wouldn't mess with a colder thermostat.

As for the rest of the story on thermostats and engine temperature....

An auto engine (gas or diesel) is just a self-contained heat pump. Lost heat is wasted energy. But several other things come into this. Above about 180ºF engine wear is reduced compared to below that temperature. (Below about 160ºF engine wear really increases). When you start getting much above 225ºF other problems start appearing. About 195ºF is just about the ideal temperature for today’s engine, based on compression and the current gasoline formulation (octane). Hummmmmm... the general at GM seems to have figured this out too!

So why use a lower/higher thermostat? Higher if you were running propane or alcohol maybe, of if your were at the North Pole? Higher leads to quicker warm-ups and quick warm-ups reduces engine wear. Lower, if you have problems with engine detonation. Higher compression, higher temperatures, higher horsepower can led to higher temperatures, which is why some tuners want a cooler thermostat.

But lower temperatures making more horsepower? Well it ain’t necessarily so in all cases. Cooler air intake can definitely help produce more power, but cooler oil and engine temperatures can cause more friction/drag reducing power. Lighter oil can reduce drag. Synthetic oil can reduce drag and friction. But lower temperatures allow more contaminates to form in the engine reducing the life of the detergents in your oil. and it goes on and on and on and on. Everything is a compromise; there is nothing free. Reducing temperature to gain horsepower through a hotter tune can cost you more wear and tear. Increase temperature can cause loss of performance. You have to decide what you want and what it is worth to you. Nothing is black or white, it all depends...

A water temp of about 165ºF in the heads, with an engine block water temperature of 205ºF, and an oil temperature of about 230ºF, would be an ideal hp producer, and give good engine wear. Something like this is tried on the "reverse flow engines" but they are not perfect, GM is still working on it.

 

[RandyStinchcomb]

Great info Bob

 

[OUR01GT]

So I should leave the OEM thermostat in by the article rjstaaf posted.

 

[Gearbanger 101]

So I should leave the OEM thermostat in by the article rjstaaf posted.

To tell you the truth, if you're car is primarily stock, you're not going to see a difference either way. Sure, you may see the gauge move a little, but performance wise.....it's not gonna do a damn for you. I'd leave the stock one in, were I you.

 

[OUR01GT]

Thanks for the info guys! I've decided to leave the OEM thermostat in.

 

[Dark Knight GT]

I'm running a 180* thermostat without any problems. My brother is going to try to run a 160 degree unit in his. We'll report back if we have any problems with it.

 

[Gearbanger 101]

You probably won't see any problems right away. The issue is the added wear that comes with running the motor at colder temps than it was desinged for. It isn't gonna happen overnight.

…lets not also forget engine oil that is polluted quicker because of the long warm up period and O2 sensors that fail prematurely for the same reason. Not to mention dirtier emissions during the longer warm up period to boot.

 

[rjstaaf]

You probably won't see any problems right away. The issue is the added wear that comes with running the motor at colder temps than it was desinged for. It isn't gonna happen overnight.

I am curious why this seems to be so popular. Does anyone have any real data from dyno runs that show what kind of gains can be had? I actually did a lot of searching on this as I have considered going to a 180 degree thermostat but couldn't find a darn bit of information on what kind of gains could be had. All I found were lots and lots of articles from respectable sources that all seem to conclude the negatives outweigh any possible gains.

Most seem to conclude that 195 is the best compromise between power and engine wear. They do mention that going down to 180 will only slightly increase engine wear but, anything below that would significantly increase engine wear. Personally, without knowing what kind of gains can be had I wouldn't mess with it at all but, if you insist on going colder than I wouldn't go below 180.

 

[Dark Knight GT]

It all depends on the driver of the car. If you're heavy on the gas, drive a lot in the summer, and/or race your car a lot, naturally, the motor is going to run at hotter temperatures than normal, despite what size thermostat you're using. I run a 180 degree thermostat with no problems at all. We can try the 160 degree thermostat and see what kind of results we get. You are right though, I'm yet to see a dyno sheet that shows any increase in power from running a cooler thermostat, though I'm imagining that a cooler motor can mean less wear on the cylinder heads and gaskets due to higher heat. However, there is the negative set of issues that you have mentioned such as build up of contamination in motor oil that can occur when the oil is unable to reach normal operating temperatures and burn the contamination off.

 

[Gearbanger 101]

However, there is the negative set of issues that you have mentioned such as build up of contamination in motor oil that can occur when the oil is unable to reach normal operating temperatures and burn the contamination off.

Covered that one already dude......I was just a little more general about it.

…lets not also forget engine oil that is polluted quicker because of the longer warm up period and O2 sensors that fail prematurely for the same reason. Not to mention dirtier emissions during the longer warm up period to boot.

 

[rjstaaf]

It all depends on the driver of the car. If you're heavy on the gas, drive a lot in the summer, and/or race your car a lot, naturally, the motor is going to run at hotter temperatures than normal, despite what size thermostat you're using. I run a 180 degree thermostat with no problems at all. We can try the 160 degree thermostat and see what kind of results we get. You are right though, I'm yet to see a dyno sheet that shows any increase in power from running a cooler thermostat, though I'm imagining that a cooler motor can mean less wear on the cylinder heads and gaskets due to higher heat. However, there is the negative set of issues that you have mentioned such as build up of contamination in motor oil that can occur when the oil is unable to reach normal operating temperatures and burn the contamination off.

This is a common myth that needs to be busted. Cooler temperatures do NOT mean less wear, quite the opposite. The tolerances in the motor are designed for a certain termperature and running the motor at a cooler temperature changes those tolerances increasing wear. Add that to the fact that you are driving around with a motor that is basically cold causing the oil contamination issues I just can't imagine why this mod is so popular.