Hello! Bigger tires with new wheels/mpg questions

Hello, I just bought a new 22' LS Manual Black in color from a dealer in Jacksonville, Fl (Dec 10). I am in South Georgia and on my first tank I got 40.5 mpg figured at the pump 7.8 gal at 316 miles. I wanted to get wheels and tires and wanted to make sure it will fit. I am leaving suspension stock. I was going to go with the setup that SparkGuy026 has 195/60/15 bfg radial t/a with advanti racing 15x7 wheels (judging by the picture). I love the white letters out! I had a few questions if I may. The tire will be 1.2 inches taller and half inch wider and 4 lbs more, the wheel will be half inch wider and 13 lbs less. So tire wheel and tire weight goes from 40 lbs to 31 lbs. My theory is if I can get my rpm down some it might be better for longevity and better highway mpg. I do mostly hwy and South Georgia is mostly flat with very slight hills.
Does anybody have any rub/scrub at all?
Does anybody have more/less/same mpg after putting on bigger tire but lighter aluminum wheels?
Better ride/less road noise?
How much less rpm with larger tires? approximately?
Will the mileage be off? (I know the speedo will be)
Thanks for any advice