just gotta find some free time. All my time is being taken up by the boat!!. I did fix a front axle leak, changed brakes and swapped the display on my head unit because the light went out. Best $10 on e-bay so far...

 

The OEM temp on a DI is 195*F.
I agree with Mike, do not go lower than 180*F.

 

I am curious as to why you guys make that suggestion? I am going to take your advice because I respect both of you guys and your extensive Rover knowledge, but I am curious as to the pros and cons of the 3 different choices.

 

The 160*F t-stat would be for extreme desert heat (hell, I'd just take it out then) and working it hard in high temps.

The 180*F would be a good all around super hot summers and mild winters but you dont want to mess with swapping it out twice a year.

The 195*F is what it came with from the factory.

If you run the truck to cold your MPG will drop, you run the risk of excessive carbon build up and no heat in the winter time.
Not to mention what a cold engine does to engine oil.

 

ok thanks for that great explanation, now for 3 more questions, how much of a difference should I notice? If I do notice a difference what should I expect to notice? and is there a way to determine what temp thermostat is in there now? (spring size, label, etc.)

 

Spike got it.. With anything, they are designed to run at a certain temp. Run cooler, and it will hurt the performance. Kinda like why you warm up a car before driving in the winter. It is like running it too cold all of the time, and 15 degrees will make a difference. If it is running too hot, changing a working stat won't help.

Just saw your new post. I got a 180 by accident and noticed my temp gauge sitting lower than it was. I went back and swapped it to the 195. Both were failsafe stats, meaning they stay open if they fail, not closed. You can stick a thermometer in a pot of water and bring it to a boil with the stat in it. When it opens, that is your temp. If you are going with a new lower temp stat, watch where your gauge normally sits. It should be a little lower at least.

 

The best way to know the temp of a t-stat is by what it says on the box when the guy at the counter hands it to you.
They are cheap, $10, another $1 for the gasket.
Just replace it.
When they fail they can fail closed, open or part way.

 

I meant how to determine the one that's currently installed, wasn't sure if the part number was stamped on the outer ring or something distinguishing like that.

 

*generally* thermostats have the temperature stamped on them.