It will help I don't know by how much? MPG IS cumulative effect from many things. Another thing that will help is a larger air dam that hangs down in the front.
95' YJ 4" lift 33"x12.5r15's D30/8.8 locked with 4:88's
USMC Jeep Club #6
"Why in hell can't the Army do it if the Marines can. They are the same kind of men; why can't they be like Marines."
Gen. John J. "Black Jack" Pershing, USA; 12 February 1918