Yes, though you'll also raise the vehicle, which may increase drag (e.g. Lexus claims a Cd .01 decrease for a 1 inch drop).
Your car and mine are vastly different, but note that by lowering my RPM 20%, my steady state
fuel economy improved by about 5%. You could use that as a starting point for some rough calcs. There are many tire size calculators out there for figuring out how a circumference change affects diameter & RPM.