I must have gotten a defective one then, thanks.
Well at least my write up shows a comparison side by side of the 2 units. It shows that you need to check these before you actually put them in your vehicle. I wonder if the people reporting high oil temps also had a bad unit?

 

I ran the 203 in my '97 but it failed shut in less than 1 year, I had about 2 mpg gain with it (hand calculated every fill up) and smoother idle. but when it failed I couldn't see spending the money to replace it and went back with a ford thermostat.

 

haha wow someone actualy close to amarillo texas

not back to subject i bought A/OX4's 203* awhile back and still aint put it on but if i rember once i do il post up my milege but if it stays the way it has been (bouncin all over the past this past year) who knows what my numbers will be

 

Yeah nobody real close to Okc either. I think we talked a little last year.

 

With the 203*, I am currrently seeing EOT's in the 180's and barely 190's, right now (mid 80's ambient). Most I've seen, this year, was 207* (peaked at this temp) after a long steady run on the interstate and then slowing down. I do have mods that help lower EGTs which, in turn, help lower engine temps. I'll have to see what the hot Texas summer brings. I put the 203* back in last summer to regain some lost mpgs when I changed to the stock stat for a couple yrs. The 203* has netted me up to 10% better mileage and EOT's haven't increased all that much. Like I've said before, "My truck likes it."

 

Thats good to know. You probably get hotter than we do here in OKC.

 

I wonder if the difference it MPG between a 195° an a 203° t-stat could be
the PCM calibration and/or tunes? I've run both with no difference in MPG.

 

Could be. I do know that my truck performs better when engine temps are warmer and the air is cooler.

 

 

I've also had both. No difference at all.

 

Actually........ no.

A bone stock truck can easily see these oil temps. It has EVERYTHING to do with the driving style, ambient temps, altitude (which makes a gigantic difference), and oil type.

High altitude driving can easily net 230-250 degree oil temps on a completely stock truck that is in perfect health. I have datalogged countless trucks, and this is an extremely common occurrence that I see on a regular basis.

 

Which is exactly what most people will see.