does anyone know if someone makes a thermostat that is over 200 degrees for the 4.6/5.4?

 

Why would you want one that high?

 

Your a nut to put anything that high in these vehicles.
They call for about 180* in the modulars (they are aluminum).
You want to blow it up early, that is the way to go?

 

The higher temp would give you a bit more fuel mileage around town under light load. Would not do it if towing, loss of power, and higher combustion temps could burn a piston.

 

If your engine is running too cool, thin out your antifreeze a bit. Too concentrated a mixture will affect heat transfer in the engine. If your cabin isn't warming up enough, you might need to replace your heater core. Unless you have a *specific* reason for wanting to do this, I wouldn't try to patch an existing problem by creating a new one.....

 

The newer computer controlled engines are not as forgiving as the older
ones. No matter what you do, the computer is going to try to compensate for the change. If its too far out of its parameters, you
will get all kinds of codes pop up and it will run like poop. Not to
mention that you are taking a chance on ruining your emissions system
and warp the aluminum heads, blow the radiator or whatever.

As mentioned earlier, fix what is wrong and keep your truck @ 180*,
as it was intended to be.

Anyway, we are curious as to why you want this?
You never did say.

 

Another thought about if you're running too cool, you could check your fan clutch. It could be locked up causing it to pull air all the time.......

 

The OP hasn't visited this site since he posted his question.

He also posted it at another site and, when it was pointed out how bad the idea was, said he's way, way up north and needs more interior heat in the winter.

He was advised that a higher temp thermostat was the wrong thing to do and he never returned there, either.

Let this thread die and stay dead.