dollars spent to improve mpg / hp. ?! Does one spend less than $1000 to do CAI, Z-tube, Crawford Plenum, U.R. pulley to acheive 300 - 325 HP & better mpg ( if you keep your foot out of it) or do you go for the Super Charger (stillen?) $5000+ with over 360 HP ? Primary goal is to improve MPG, while the fun side of me (why we bought FX) is to +hp. ...$2 bucks a gal. , oh man!