160 degree Stat worthless

A 160 just lowers the initial opening temperature, you still can run at 200 degrees or more, thereby creating wide temperature variations to and in the block and heads. You want your engine as HOT as you can get it without pre-ignition (which triggers the Knock (timing) Retard). Efficiency of the engine goes up the more heat the cylinder heads retain - up to the point of pre-ignition, all other things being equal. So you want it just cool enough so that the PCM does not retard the timing. A cool engine draws heat out of the combustion process - less vapor (combustion) pressure, less ability to do work (push the piston down). Not to mention the possibility of oil contamination from unburned fuel (due to lower temps). Pre-ignition can be reduced also by using higher octane gasoline. Reducing the temperature also impacts the ECT sensor, as discussed above in "PCM Operation." The reported ECT set temperature is 170 degrees, thereby forcing the PCM into Closed Loop Condition by "timing out." At which point the the desired goal of increasing the fuel enrichment goes away anyway, as the HO2 sensors will control the enrichment to maintain 14.7:1.

i melted the engine in my 91 camaro with a 160 stat. my fan was kicking on at 190 degrees and the car always run at 220. it was like that 2 years until the tranny went and it started knocking (ready to throw a rod)

so the thing is still a bad idea right?

yes, unles you have a power programer to program your ecm into turning the fans on at 155 or 160 degrees. see no one told me that this had to be done. and it was a costly mistake. i had to get rid of my car cause the block was cracked. it got so bad that when it got to a certain temp it would cut off and wouldnt run right.

but the best thing that you can do is just go up to that counter and tell them what year and engine and tell them you want the factory required stat for your car.

I put a 160 in my car and it works great...runs about 175 on the highway and 185 or 190 in town. no programming or anything.

The 160 degree stat will have no negative effect on your engine if you program for it and yes you do need adjustments to your ignition timing advance, air/fuel map and fan kick on and off temps. Using any product where the computer thinks your using a different product will have a negative effect. Such as if you change your fuel injector's to 36 LB injector and the computer thinks you have the stock 24 lbs your car will run rich and cause back-firing and missing but tune for the new injectors and you will show a power gain.