Thermostat poll, 160 vs 180

[Bob Yates]

I've been into chevy cars for 38 years and a 180 stat gives the best all around performance. As a one time GM tech all the masters have told me 180 and that's what I use in my 86 C4. The 195's are for better emission control. That's what I know.....Bob Yates

 

[warren s]

I have been running a 160 degree thermostat for 2 years. In conjunction with the fan override switch I can keep the coolant temp with 100 degrees of ambient temperature.

The Oil and transmission fluid temp. also stays with 10 degrees of the coolant temp.

The first few months I had the car it ran between 190 and 230. The fluids smelled burnt, I was getting an average of 23 miles per gallon, and my best time in the quarter was 13.6 at 101. Since I changed to a 160 degree thermostat and use the fan switch I now get and average of 25.5 miles per gallon, best ET was 13.39 at 103 and the transmission fluid and oil smells like new. The engine also stays noticeably cooler. Since I replaced many vaccume lines and hoses with the thermostat change, they still are fresh and pliable. I put on about 10,000 miles this way. The car also seems much more responsive in hot weather. I did the throttle body bypass too. I pass emmissions by a wide margin.

The 160 works great for me. I went from a 195, never had the 180.

 

[Vettefan87]

This might not be the answer but while me and my brother were driving back from the cruisfest i noticed that the oil temp was running about 215 and the coolant was about 162, so thats a little over 50 degrees, and thats not even the combustion chamber, which is even hotter. So I am going to run a 180, im not going to risk harming my rebuilt engine.

 

[Vettelt193]

I suspect it will still run at 200 - 210 just will take a little longer to get there.

Exactly... it takes a bit longer to get there.... which means you will have the fans run a bit less, and the car will be a bit cooler for longer.

As for the C5 engine, different beast... And honestly, GM doesn't do what is necessarily right for the car, they do what is right for their wallets. In the C4 era, they put hot thermostats in (as high as 195 degrees) for emissions purposes. It had nothing to do with performance or otherwise.

All in all, if you have a 195 degree stat, trash it... get a 180 or 160. there really isn't much of a difference between the latter two for actual running temperatures (might be as much as 10 degrees in optimum conditions, most of the time it is probably around 5 degrees). there is a huge difference between the 195 degree stat and either a 160 or 180 though...

 

[Bob Chadwick]

We're talking a very short time here, not hours. Think of how little time that it takes your car to warm up.

 

[Vettelt193]

for sure, especially when comaring 160 to 180.

 

[warren s]

If you control the fans the engine will run much cooler with a 160., all the time.

Replacing the therm. by itself is of little value. Unless you drive exclusivly on open highways.

 

[Mad-Mic]

i run a 160 in my L98 vette. my best run came at 130 water temp when i was staged. at cruising speeds i run about 162.

both the LT1 and the LS1 are built to run at it's best at 180 degrees. the L98 runs it's best at 130-140 degrees.

if thermal shock was the case i would of broke this car along time ago because i drive it like it's suppose too be driven so one minute i can see 230 degrees on the water and above 240 on the oil running the snot out of it and turn down on a hwy and do 65 and 5 mins later be 162 water and 215 oil. ( i have no switch and or chip for the fans yet) i've put 30k pretty hard miles on my vette and you guys are argueing longevity? keep your oil changed and use synthetics and your motors and trans will last a very long time if you granny the car. if you race it like i do you take the chance of hurting something but in a stock application i know of guys getting 140k+ miles out of hard beat on cars that run in the 11's on long blocks running juice.

it all boils down to 2 things. if you want more heat in the wintertime or not or you want to go just alittle quicker in the 1/4 mile.

in my car the difference between 140 degree water temp and 180+ degree water temp is 2 tenths in the quarter mile.

 

[Mart]

This is exactly what I've been thinking,:BOW :BOW :BOW way to go Mad Mic.

 

[warren s]

2 tenths is nothing to sneeze at !

 

[Tanreall]

I think I'll take a 180 over a 160 any day keep my car in good shape and if I want it cooler I will buy an aluminum radiator and a fan control switch which will actually make my car run cooler not just take longer to heat up. Thermostats don't make your car run cooler just longer to heat up I think there is some misconception about the 160 actually making the car run cooler for some reason.

 

[Mad-Mic]

your right but if your car is in good working order it should run aruond 160 on the hwy which i do but sitting in traffic like at Hot Rod week in Ocean City i seen temps at 230 but mostly in the 190 range.

reason i don't have a fan switch is because i want my interior to stay as stock as possible. the only thing i will add is a small bullet style shift light when the time comes.

 

[Mad-Mic]

2 tenths is nothing to sneeze at !

it is if your going after a stock A4 TPI record

 

[Mad-Mic]

This is exactly what I've been thinking,:BOW :BOW :BOW way to go Mad Mic.

thanks Mart, just figured i'd give my real world advise on this 160 or 180 IMO won't hurt your car. BUT 160 to 180 is almost 20 rwhp which too me is simple to know i rather have the extra HP i've proven this in time slips by hot lapping the car from cold (150 degrees) to hot (190 degrees) and the difference was almost 2 tenths.

13.19 and 13.35.

i've tried 120 130 140 150 degree runs and my best so far comes between 130 and 140 degrees. what does this prove? nothing really but i can easily dial the car's ET in at the track if i know what my water temp will closely be when i stage the car.

 

[Tanreall]

I really doubt that its 20 rwhp. There is no way that opening a valve 20 degrees sooner can have that big of an effect especially when its been proven that 180 is just about perfect for power.

Now if you told me that you have your fan setup to run at about 175 and had an aluminum radiator that kept it in the 175 - 185 range I would believe that you could get maybe a few ponies at the wheels compared to a car running at 210 but from 160 to 180 not going to believe it till some one rubs my face in some numbers and a dyno sheet.
People just want to believe that really cheep mods will make more power.

 

[Mad-Mic]

I really doubt that its 20 rwhp. There is no way that opening a valve 20 degrees sooner can have that big of an effect especially when its been proven that 180 is just about perfect for power.

Now if you told me that you have your fan setup to run at about 175 and had an aluminum radiator that kept it in the 175 - 185 range I would believe that you could get maybe a few ponies at the wheels compared to a car running at 210 but from 160 to 180 not going to believe it till some one rubs my face in some numbers and a dyno sheet.
People just want to believe that really cheep mods will make more power.

people that know me know i'm living proof cheap mods work with alot of tuning. with my 500 bucks in mods i'm hovering in the 13.0 range on a 2.59 geared A4 vette. i ran the car back to back from cold to hot as mentioned above and the car was almost exactly 2 tenths off in difference. we all know 1 tenth and 1 mph = 10 rwhp how much proof do you need? BTW this is on an L98 car not an LT1 which is a big difference since heat affects SBC I blocks more.

 

[Bob Chadwick]

.2 of a mile is not very much difference in time. I'm sure you are a good driver with a lot of experience but could it be just a better run?

 

[warren s]

I really doubt that its 20 rwhp. There is no way that opening a valve 20 degrees sooner can have that big of an effect especially when its been proven that 180 is just about perfect for power.

How exactly has that been proven?

I picked up 2 tenths and 2 MPG by running a 160 therm and a fan switch. (Five bucks for the switch and some wire)

 

[Tanreall]

Have you ever taken a physics course before?

If you have then you know in a perfect world (which doesn't exist) the best temp would be as hot as the metal could stand, due to the fact that the combustion gets more efficient the hotter the burn but in this imperfect world we live in we have to settle with what we can get which is around 180 I really don't feel like wasting my time to type the whole theory so look it up yourself and research a topic before you go posting on it.

 

[Tanreall]

ok I'm done with this I love all corvettes if yours gets faster that awsome keep smoking the rustangs and save the wave.


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