my ta runs about 170 in general is that too cold?

Yes, especially on a FI car.

Too cold & the ECM won't go read the sensors & not run as well.

My cars generally run around 160* by the factory gauge with a 180* thermostat, all the proper ducting, air dam, etc. 170* should be just fine.

The stock gauges aren't very accurate.

Yes you can run too cold.

do you live in the north pole?

Running too cold constantly can cause acelerated wear throughout the motor on top of the above mentioned EFI issues that can lead to extended periods of rich fueling that can contaminate the oil and cause even faster wear.

Late model cars typicaly run in the 190-220 range.

my car never gets past 150 or 160 and its a 1991 350 z28 . The fan is hard wired and runs all the time .........
Could it be the thermstat or just the fan running all the time ?
My mechanic doesnt think the fan running would cause it to run cold all of the time .

It might be time for a new thermostat... I run a 180 degree thermostat with constant cooling fan... I tried the 160 and it ran too cold, not to mention it ran like crap, don't know if it was cuz it was running in open loop ...

The colder an engine runs, the more efficient an engine will run. If u think about it, the colder air is, the more dense it is so u will actually have more air in the combustion chamber than if the air is hotter.

Not exactly, especially on fuel injected cars.

If the temp is too low, it uses the preset tables to run the engine & aren't using all the sensors to fine tune the performance good, so it isn't as good as it could be.

Then there is that a hotter engine (190-200-ish) burns cleaner & produces better emissions results.

I don't think this would be the case on a computer controlled vehicle... 180 was the sweet spot, I tried running my car with a stock thermostat and a fan switch which would kick in at 220, and freaking car felt like a boat anchor... wired the fan directly, swapped the thermostat that same day and wow...

yeah but i know no other info about his car so he could have swapped a carbed motor with no ecm. So im just saying in general that non-computer engines are more efficient (they produce results with minimum effort, resources, or waste) at colder temperatures. I never said they performed the best (hp and tq) at cooler temps. I do believe that there are other exceptions tho.

Ok, you're pardoned...

180-200 is generally a good range, I tried a 160 in my 355 for a while and it was a dog. it liked 180.

Maybe I missed it, and I could be talking outta my rear, but it seems no one has even mentioned the choke on carbs, just alot of FI mentions. There seems to be plenty of reasons that running too cold is a bad idea.

I only understand a small amount about motors but.. this is what i get...

Be it computer controlled, or carbed, TBI, TPI, etc, MFI, whatever... SOMETHING controls the choke... and unless you have a manual choke cable from your carb all the way thru your firewall... having it run under operating temp is going to affect the fuel/air mixture.

"Cold Idle" happens on every fuel injected car that still has all its proper components. I live in michigan, and it gets mighty cold 5 months of the year... I used to own a BMW 325Ci that we put a M3 turbo motor in... Ran like SHI* because the intercooler was too big... Never got outta cold Idle.


something else to mention... I saw someone post an idea that the colder air = better combustion... which is true... but thats the AIR INTAKE, not the block temperature, and doesn't even take into account idle rates and fuel mixture.

It depends on the car and how you build it, some cars like 180-190 some 220....during dyno runs with mine it made the most power around 180 range.

I ran a 180'F high flow which caused me to run below the 170 mark on my gauge.
I lost MPG on a little 500 mile road trip. I should have gotten at least 22-23mpg, but running cold I got barely that.

The choke in this case I wouldn't include in the box of worms when it comes to running too cold... it doesn't take that long for the choke to fall back into the background, as the temperature it needs to release isn't that high, I don't think it's nowhere near the 160 degree mark, but of course I cold be mistaken as It has been a while since I have let my car run till it releases the choke... typically since I am not driving it and have a small fuel leak, I fire it up for about a minute, stomp on the gas about 10 seconds later so the choke lets off, dropping the RPM by about 500 rpms... so dont' really have an answer for that one, at least not off the top of my head...

So you drove 500 miles with your thermostate bearly open and the only way coolant was circulating was threw the 3 drilled holes in you thermostat. Hard to believe.

When we're talking about combustion, the most efficient engine will be the engine that burns the gasoline completely and thoroughly. Anybody who has tried burning wet wood in an open fireplace knows that it performs poorly. Dry wood in a wood stove works infinitely better. Same with cars. A low coolant temp car won't burn the fuel completely.

I asked a C4 Corvette guy to check the instant fuel economy on the highway (digital read out in those cars as is the engine coolant temp) at 160, 180. and 195° coolant temps.

160°F = 1.5 mpg fuel loss.
180°F = 0.5 mpg fuel loss.
195°F = baseline.

Now to take matters to the extreme, when you get into northern Alaska in the Fairbanks region, people will often leave their cars running when they go to the mall or grocery store. They do that to save fuel and pollute less. That's because the extreme cold weather there gives such HUGE cold start emissions and very poor fuel burning, that keeping the vehicle running and up to temperature actually burns less gas.

An easier example would be a human jogger. You're going to run better when it's 60° outside than when it's 100° outside. But you won't run very well if it's 0° outside.

Those numbers are based on a computer controlled car. Carb cars vs computer controlled is a big difference. Computer controled cars are designed to run hotter. Carb cars can easily run from 160-180 and run very well and efficent at those temps.

my little motor loves the cold.
in the summer i run with no thermostat and fan hard wired, car stays at aroun 155 and feels much better then when i put a 160 or 180 in

"the only way coolant was circulating was threw the 3 drilled holes in you thermostat"
I don't drill holes in my thermostat, only morons do that. I bought a mr. gasket 180'F thermostat for less than $10.
I have a full flow thermostat bypass so what ever coolant can fit through a 5/8 heater hose gets bypassed to the cool side of the radiator. So even when the thermostat is closed a lot of coolant is circulating throught the block.
I have not had good results running my car cold.

My car runs best when the temp is between 180 and 195.

And the guys with the factory guages saying your car runs at 150-160 with a 180 thermo, your guage is not reading right. You will run at at least thermostat temp. I had the factory guages in my car when I first started driving it. I then got all Auto Meter guages. My temp started showing over 15 degrees warmer. I trust the new Auto Meter guage more than a 19 year old factory guage.

Funny you think only morons do that. I thought only morons bought cheap mr. gasket stuff for there cars. That 5/8 coolant hose isnt going to cool your car if your thermostat is closed.Especially on a 500 mile trip.