I'm getting ready to do the next round of mods to my truck. I've been doing some searching on a lower open temp thermostat. I would like to run a bit more timming but I don't want to loose MPG. So is it worth it?..........

 

its worth it and why not its crazy cheap mob

 

I don't know if its worth it are not, I bought a 180* stat and it didn't change my ECT any. Still runs the same 195ish. I'd get at least a 160* if you do.

 

i have a 160* stat. Before the DMAX I/C mt ECTs were 180* all the time. Now after the I/C install they run 185* while cruising and 195*-200* at idle.

 

I like to keep my coolant in the radiator as long as possible. with a 160 the coolant is just cycling right through without stopping. with a stock thermostat it will stay in the radiator long enough to actually do something. For those of us who do need to worry about temps, I would stick with a stock thermostat IMHO.

 

Wouldn't a 160* thermostat just open before a 190* and allow cooling of engine block at an lower temperature? I cant see how it would make the radiator fluid cycle any faster or slower

 

just my thoughts....so bear with me.

with a 160* thermostat the the coolant never really gets a chance to cool down enough because the thermostat opens so soon, and basically stays open, so the water pump just continually cycles the fluid. with a 180 or 190 the thermostat will stay closed longer, and allow the coolant to stay in the radiator long enough to cool down. It is almost like running without any thermostat at all since the 160 would pretty much stay open all the time.

I had an overheating issue every time I towed a few years back cause I was running a 160* in one of my older trucks. As soon as I put a 185* in it, the problem went away. With the increased load that a s/c puts on the motor, the coolant needs all the time it can get to cool down. Under normal cirumstances the 160* may help, but I think in a f/i situation, it hurts...

 

I have read that there are certain operations of the engine that function as designed at the higher temp and that they may not at a lower temp...but what is our stock thermostat...190? I still have the stock one, my trucks gauge reads around that, but the OBD II reads higher on my Predator while driving...200+...

 

Ok so while the T-stat is closed air is cooling the fluid in the radiator only. When the t-stat is open, air is cooling the fluid in the radiator and engine block. Fluid moving thru the radiator gets cooled.
The purpose of the radiator is to exchange heat from the engine, by cooling the fluid in the radiator. If the t-stat is closed you dont exchange. I am no mechanic, but it seems logical that an open t-stat is going to cool the engine and a closed one wont. As far as the proper temp? I've no idea.

 

There is some truths to this theory but don't know how much of it is effected with our trucks. Not all our trucks have the same size radiator so that needs to be considered with how long the water stays there. I have the largest one in mine and my 160* thermostat runs 175-180. This is the first I have ever seen in a vehicle, everything I have ever had before (hot rods or DD) and they ran right at the rating of the thermostat. I had a very large overkill radiator with a 409 sbc and a 160* thermostat and it wouldn't warm up anywhere close to 160 in the winter and I had to put cardboard in front of the rad and pull the fan off. I change t-stats so it wasn't sticking open.
But all BS aside, my stock tstat ran around 195-200* and the 160* runs 20* cooler all the time.
If you are wanting to push the edge with your boost level and or just ignition timing then theoretically the cooler the engine the less heat in the cyl. Heat is one of the main contributing factors to pre-detonation (knock).