Engine operating temp

[Dcarver99LT]

What is the correct operating temp for the 5.7? Right now I'm running at 155-160. I thought it was supposed to be 190-210. Could the t-stat be opening too early? I think I'm suffering some fuel economy because of this. Got 18mpg running 65-70 with about a 15-20mph tailwind for 500 miles and I've got 3.42 rear end

 

[lesterl]

Op temp is 195* +/- ..... Suspect a sticking open stat or a "hot rod" stat @160*..... 18MPG isnt horrible, what do you have?

 

[Dcarver99LT]

I've got a 99 2wd tahoe. I couldn't imagine why the previous owner would put a "hot rod" tstat in a bone stock tahoe

 

[lesterl]

IDK, some people think that it is the way to go.... I like my 195*, if I were to have a vehicle that I towed with alot, I might put in a 180* stat.....

 

[Dcarver99LT]

Well I've now got torque app pro and it shows my temp to be 195. So I guess my dial in the Tahoe is broke lol

 

[lesterl]

My 98 Sierra reads like that, Datastream shows 195 on the money......