You want to run the highest temperature thermostat you can and still keep the engine cool under all conditions.  A 195 would be my first choice, but may present cooling problems.  My next choice would be a 180.  I would never run a 160.  If it can't be kept cool with a 180 there's something wrong or mismatched in the system. 

Why is hotter better?  Two reasons, first, the hotter the engine runs the less wear it endures.  Engine wear is not linear based on temperature its exponential, so running an engine say 20 degrees cooler doesn't make a seemingly insignificant increase in wear, rather wear actually doubles, meaning the engine wears out in half the time.

Second, engines make more power the hotter they run because the fuel is atomized better.  Ideally you'd want the fuel literally vaporized, but that takes all kinds of trickery beyond what we're talking about here.  This increase in efficiency is one of the reasons why automakers went to higher temperature t-stats when emissions compliance became harder and harder to meet.  Efficiency is also power, because what was formerly wasted is now recaptured and put to work spinning the crank. 

TKOPerformance wrote:

You want to run the highest temperature thermostat you can and still keep the engine cool under all conditions.  A 195 would be my first choice, but may present cooling problems.  My next choice would be a 180.  I would never run a 160.  If it can't be kept cool with a 180 there's something wrong or mismatched in the system. 

Why is hotter better?  Two reasons, first, the hotter the engine runs the less wear it endures.  Engine wear is not linear based on temperature its exponential, so running an engine say 20 degrees cooler doesn't make a seemingly insignificant increase in wear, rather wear actually doubles, meaning the engine wears out in half the time.

Second, engines make more power the hotter they run because the fuel is atomized better.  Ideally you'd want the fuel literally vaporized, but that takes all kinds of trickery beyond what we're talking about here.  This increase in efficiency is one of the reasons why automakers went to higher temperature t-stats when emissions compliance became harder and harder to meet.  Efficiency is also power, because what was formerly wasted is now recaptured and put to work spinning the crank. 

What he said! Google engine wear vs temperature. I60 Tstat was popular with the 5.0 guys because it tricked the computer to thinking the engine was still warming up and richen the fuel mixture
 

Last edited by Huskinhano (1/02/2019 8:02 AM)

I tried everything from 160 to 200.  180 works best for me.

Huskinhano wrote:

TKOPerformance wrote:

You want to run the highest temperature thermostat you can and still keep the engine cool under all conditions.  A 195 would be my first choice, but may present cooling problems.  My next choice would be a 180.  I would never run a 160.  If it can't be kept cool with a 180 there's something wrong or mismatched in the system. 

Why is hotter better?  Two reasons, first, the hotter the engine runs the less wear it endures.  Engine wear is not linear based on temperature its exponential, so running an engine say 20 degrees cooler doesn't make a seemingly insignificant increase in wear, rather wear actually doubles, meaning the engine wears out in half the time.

Second, engines make more power the hotter they run because the fuel is atomized better.  Ideally you'd want the fuel literally vaporized, but that takes all kinds of trickery beyond what we're talking about here.  This increase in efficiency is one of the reasons why automakers went to higher temperature t-stats when emissions compliance became harder and harder to meet.  Efficiency is also power, because what was formerly wasted is now recaptured and put to work spinning the crank. 

What he said! Google engine wear vs temperature. I60 Tstat was popular with the 5.0 guys because it tricked the computer to thinking the engine was still warming up and richen the fuel mixture
 

The irony of that is that from the factory the 5.0 cars ran faster if you leaned them out.  The factory calibration was always on the rich side to prevent engine damage from running on the ragged edge, but as the saying goes leaner is meaner. 

The 160 degree t-stat goes in the same bin as the guys who removed the coolant lines going into the EGR spacer and capped them because the air would be cooler without being heated up by the coolant.  Unfortunately for them they exact opposite was true.  Intake temps went up by about 100 degrees without the coolant circulating.  As it turns out the coolant did what coolant is supposed to do; it cooled things down.  Ah the early days of modifying computer controlled cars.  It taught me that people don't understand computers, or cars for that matter. 
 

I think that it's about time for MS and Mr. Tim to have their friendly discussion on the merits of thermostats, radiators and how the engine gets cooled.....right, MS?