what is the proper full hot operating temp on a 98 d16y7

only reason i ask is i started getting kinda bad gas mileage so i had my matco scanner hooded up and say LTft at -6 and STft at about -5 and they stayed roughly this way wile driving idling pretty consistent.

i looked at running temp and it was only 177-180 no heat or ac on and about 85-90 out side temp. honestly iv never had a car run any cooler than about 205 most where in the 210 range. i will be getting a hold of a friends lazer pointer thermometer in a day to two to see if the reading is matching actual temp.