I have an 04' Titan 4wd with a PRG mini lift and Nitto terra grapplers 32060R18s a magna flow and Nismo Cold air intake. I average 12-13 mpg. all around. I went from 15-16mpg down to 12-13 with the wider heavier tires! Does this seem normal??? I have a heavy right foot and 153K on her but have had this set up for years. Anyone getting better mileage with similar setup??? Thanks!