Nissan Repair: mileage 99 path, flowmaster muffler, better mileage

Question
99 pathfinder 4wd 3.3 ltr v-6.  Milage about 21 mpg highway w/o AC running.  Should I get any better?  The front hubs seam to drag quite a bit while i have it up in the air.  Im guessing with auto locking hubs that is normal.  Prob. not great for milage though?

Answer
Tim,

You could disassemble the brakes and clean the slides and pins and grease them per the maintenance manual.  Also, make sure the tires are up on air.  Get a K&N filter for the airfilter.  Use synthetic oil and get a free flowing exhaust like a Flowmaster muffler and that would help too.  Make sure the timing is spot on and that the plugs are changed recently.  The mileage you state is normal.  But, there are the ways I mentioned to get better mileage.