Thanks for all the input.
I installed a new Super Stat 195* today.
Will check everything over tomorrow for a vacume leak and report about the idle.

 

half way through this thread i spot "my *** dyno felt a power increase" haha thats great. my mopar pcm and way high shift points as there no rev limiter with it loves a 180 t stat. i d be doing not so good with a stocker. i just hate it when it gets to -10 here in alaska in novemeber. which is unusual.

 

damn.. i fell victim to the dual post split personality guy. guess that proves i shouldve read all 6 pages through first lol. indeed a good post. after working at a good auto parts chain for 5 monthes im no genious but i definately have a better understanding of this stuff.. and what to change and not change on my truck.. its been 4 monthes since iv been on here.. glad to be back and learning

 

I think everyone fell victim to our bipolar buddy for most of this thread.

Glad your back, and it is a great place to learn

 

According to my scan tool..Matco Determinator ....as I recall....my 95 5.2 goes into closed loop at 140 degrees, so at that point the computer uses the 02 sensor to keep the fuel mixture at 14.7 to 1. So if it runs 180, or 195 degrees shouldn't the fuel mixture be the same? My long term trims are pretty close to 0. So the computer isn't adding extra fuel or it would show up there.

I have seen vacuum leaks show a +25 on the trim where the computer is adding extra fuel to try to get to 02 sensor to switch between rich and lean. Like I said I never lost any mileage with 180's in either of mine. Winter mileage will suffer because the cold air is denser ....more oxygen...so more fuel to keep it at 14.7 to 1 which is more related to intake air temp than a 15 degree difference in engine temp......As a side note...had a 96 Dakota 3.9 in the shop today, clogged oil pickup tube and a pan with a mess in the bottom. Owner says he does regular oil changes??? .....I will keep my 180's in mine.

 

If you have a MP PCM, then it may go into closed loop sooner. Even Fords will run a bit richer @ 180*. My Mustang does. With the more aggressive timing advance, you will probably benefit from the cooler temps to keep detonation away. On a stock tune, with a stock PCM, nothing to really be gained.
One of our admin's runs a 180 stat in his 04 Hemi to keep it running richer due to Long tube headers and better flowing exhaust. So it does make a difference. His runs too lean @ 195.

 

Took the truck for a drive, about 36 miles.
Idle is now steady, seems a tad low, but steady.
Will have to check fuel milage later.
This is where it runs now with the new 195* Stat, same as before with old 195* Stat.
Seems high on the gauge, I'm wondering if my gauge could be off.
Is there a way to check the actual Temp, aside from what the gauge says ?

First pic is parked in drive
Second pic is driving up the HWY.

 

I've got a 195F thermostat (second one, tested to actually open at 197) in mine and it has never made it to the 200 mark, even in stop and go traffic in 115 degree heat with the engine fan roaring -- must have been 125 or 130 on the pavement, at least. Rather than fool with it, I just learned what is normal and only get nervous if it goes too far above that.

The best way to check the actual temperature without getting silly about it is to buy, beg, borrow, or steal an IR thermometer and aim it right at the base of the thermostat housing after the truck's good and warmed up for a while. It's not so easy to get at, and the reading will be a couple/three degrees low but close enough.

 

i got a 195 t stat today gonna swap it in and toss that 180 out tomorrow after i do plugs and fuel fitler on the parents 2000 ford explore

 

I think you couldnt have said it better. so many factors out there to really identify any one thing benefiting or harming mpg or power. if it works.. it works. if it dosent then switch it. the tune I see but headers or temp and humidity in the area. it makes sense to go with the "norm' well said unreg.