Engine Temp vs MPG

[JanGeo]

I emailed Synlube this morning and found out that I am really doing well in the MPG department. My question was if my engine temperature was in the proper range for best mileage as it seems to like operating a little higher than 182F - seems the idle comes down a little at 186-188F but Miro says that the EFI computer uses a little extra gas injection to cool the engine when the temp gets a little high. Also the AC lowers FE by about 10mpg in Cali at least. Anyone ever checked engine temp vs MPG while monitoring Air Fuel mixture ratio?