Grille mods, self made - to cut drag, boost engine temps
 

https://cimg1.ibsrv.net/gimg/www.che...9b9eaeda09.png
Final goal-- headlights taped off, all grille "nostrils" filled and front upper silver grille painted black
https://cimg8.ibsrv.net/gimg/www.che...30bba242e4.jpg
Nostril filled w foam insulation as a backer to support "garage sale" sign cover cut-out
https://cimg7.ibsrv.net/gimg/www.che...7e796ff03f.jpg
Done--passenger side
https://cimg9.ibsrv.net/gimg/www.che...f757202b69.jpg
DS - another view
https://cimg3.ibsrv.net/gimg/www.che...b3efaee9ac.jpg
Driver's side (DS) foglight nostril covered w black duct tape

Why in the world would you want to boost engine temperature? Not that doing what you have done will do anything at all to change the engine temperature.

Duct tape? Not sure what to say on that.

Why?

If this is competitive hyper-miling;

The engine temperature should be "optimum", 1185F, not "as hot as you can get it. You have computers in the car working on MPG.

If you are worrying about .001 MPG, you should be looking at the gap along the hood, covering wheel openings, closing the gaps around the doors. Maybe adding a Super Bee nose cone

If not competition, work on your driving techniques long before you start modifications.

I agree w/ Greybeard: Why ?

Sometimes I wish Chevy never had the digital temperature readout, as some owners get totally fixated on monitoring the temperature which does fluctuate as designed. It is handy when diagnosing some cooling issues (ie: thermostat jammed open), but not necessarily for day to day monitoring.

And it is called a cooling system rather than a heating system for a reason. ;)

Some of the whacko hypermilers believe that the hotter the engine the more complete the combustion. Which may have been true to a point, before the combustion was controlled by computers.

Now the stoichiometry is controlled by the computer. It takes a bunch of data from the sensors and tries it's best to keep the A/F at 14.7:1. Raising the engine temp is an attempt to get the A/F to lean out mechanically, but the computer sees that and enriches the mixture in an attempt to cool it down. In other words: chasing your tail.