I am aware of the temperature difference due to the location of the temp sender. But the real question that is never answered in these threads is why you want your engine to run cooler than the engineers designed it to run. Why didn't GM put 160 F thermostats in the cars originally?

 

More power!!!!!

Check at what temperatures the computer starts pulling out timing.....I think that is the main culprit..

 

Internal combustion engines make more horsepower with increasing coolant temperatures, NOT LOWER. Auto engines are heat engines, lower coolant temps pull heat from an engine, heat IS horsepower. Continental Motor Company proved this in real engine tests by running the same engines on a dyno at different coolant temps and found that HP increased with increasing coolant temperature (heat is hp), they also found that the engine became more efficient, it made higher HP with lower fuel consumption , HP/lb fuel flow, they tore down the engines and compared cylinder bore diameter with the starting dimension, cooler engines had more wear. Even Smokey Yunick in his last book said that race cars get their peak HP at 250 to 260 F coolant temps. I also found on the net a guy who ran HP vs coolant temp dyno tests and published the dyno charts on a Jeep he owned. The higher coolant temps made more HP.

 

I installed a 160 thermostat last summer & the only thing I noticed is it takes alittle longer for the engine to get hotter.I'm still dealing with the engine getting too hot for my tastes(235 degrees F).The heat still works good whe driving the car in 30 degree weather when engine is 173 degrees.WW

 

???engine heat is energy that wasn't converted to useable power????

I agree combustion engines can make more power with increasing temperatures IF you can control issues like detonation......

 

First, 235 F will do no harm to anything in the engine! Also, 235 is high and probably because your radiator is jammed with debris. C4's pull air in from near the road and radiators get clogged with straw, cigarette butts, plastic bags, dead grass cuttings and all manner of debris. If you bother to clean out your radiator, you will do much much more for your engine temperature lowering than with a lower opening temperature thermostat!!!!!!!!!!!!!!!! It isn't the thermostat that cools your engine, it is the radiator.

 

Lower coolant temperatures steal heat from the combustion chamber, ie...the cylinders. If you want more HP, then you are asking for higher pressures and temperatures inside the cylinders.

 

I put a 160 thermostat in my engine because when I leave work, I go through about 6 stoplights. By the time i went through the third light at creepy crauly speeds, the engine was at 230 degrees with an ambient air temp of 115 degrees.
NOW....
I can get through all 6 lights before my engine hits 200, and it doesn't go above the 200 degree mark all the rest of the way home. Make your car work the way you need it to.

 

did you reprogram your fan settings ?

 

What is wrong with a 230 temp?

 

Nothing at all.

I agree with everything jfb said.
GM engineers are not as "stupid" as some want you to believe.

My '96 is completely stock with over 107,000 miles.
It runs in the 195 - 198 temp range when moving.
When stopped it will climb up to approx. 235 F max.
Never got any hotter than that.

With the correct amount of coolant and the correct system pressure, the boiling point is approx. 260 F.
Anyone that says their car "boils over" in the 230 - 240 range does not have the proper coolant mix and/or pressure in the system.

 

I do not want to start an argument but I am going to point some out some errors in assuming all engines will work better at higher operating temperatures on pump gas. Some engines may work better at low temperatures and some may work better at high temperatures.
-If the engine does have any detonation or preignition at WOT it will make slightly more power at WOT with higher operating temperatures
-If the engine experiences detonation or preignition reducing operating temperatures until those conditions disappear will increase power

On the dyno I use on a regular basis most cars produce more power at 160 degree water temperatures than at 200 degree water temperatures. This is due to reduced or eliminated detonation and air intake temperature increase which results in reduced timing. I say most cars because once in a while we run into a car which makes just as much power at 200 degrees as it does at 160 degrees. (The ratio is probably 10 to 1) You notice that I have not said anything about gas mileage because I believe the higher operating temperatures will slightly increase efficiency or gas mileage at part throttle. (The owner needs to determine what is more important to them increased power or slightly increased gas mileage)

If you could run high octane race fuel all the time I would run higher (195) degree operating temperatures but since I am limited to 93 octane pump fuel I lean towards lower (160) degree operating temperatures if power is my main concern.

 

Too close to overheating temps imo. if you sprung a leak youd have a lot better odds at catching if say it was running at 200 rather than 230-240. You dont need that much damn heat for the car to be efficient they already are it just helped them with emissions running them warm. Will 230 kill the motor no but will bake things underhood quicker.

All I can tell you is running a car with a coolant temp under 200 shows a diff on the dyno and time slip rather than 220 guaranteed.
Opinions will vary

 

One of the big reasons for the higher factory temperatures is that the GM engineers were concerned with meeting emissions requirements.

I prefer it to be a bit cooler so went with the 160 and reprogrammed the fan on/off points.

So unless a GM engineer is going to pay for fuel and maint I'm not worried about it.

 

Was the first point above supposed to say "If the engine DOESN'T have any detonation...."? Both points make more sense that way.

BTW,,,It seems like I've read where 160 stats end up causing more internal sludge/contaminants in the crankcase. It's true that engineers set temps for a reason. (I think it's emissions.) When lowering temps, there should be another reason. In my case for example, higher compression and the elimination of EGR prompted it. (I'm installing a whole new motor.)

When I discovered the purpose of the EGR, I found it's there to dilute the AFR with exhaust fumes. That slows down the process of combustion so engine/combustion temps can lower. IOW, the cooling system alone (as designed) is not sufficient to control temps. That's a big reason I decided to make a change. I've made several adjustments to acheive target temps from 180-205. I believe that's more reasonable, eliminates the need for an EGR, and is necessary for my higher compression. A 160 stat seems unnecessarily low.