Forget the so called performance air filter.  I know the ads sound good
but it's all bogus under real life conditions with stock engines.  Same
for TornadoAir.  The feel of a bit more power is mostly the change in
the sound level and frequency from the change in airflow.  No practical
result.  This stuff has been checked out many times and found to be
basically useless on a stock engine.  Based on my '98, your 15-17 mpg is
about as good as you're going to get, even with a light foot.  I got 19
mpg a couple of times on my V6 on 250 mile trips(all highway), but I
found it so aggravating to drive that way (keep a relatively low
constant speed) that I went back to my normal driving.  Good luck.

Ken

DFastOne wro

I have now driven a similarly equipped '98 for quite a few years. Your
mileage makes perfect sense. If your commute is on low traffic, rural
highways at a constant 45 MPH you may be able to squeeze up to 18-20 mpg
with your light foot. If, on the other hand, it's on a 70 MPH hilly freeway
like mine, even 15 mpg is a nice accomplishment. City driving will be even
worse.

It's a heavy vehicle, and the constantly engaged all-wheel-drive is also
taking a bit of a toll. Your 5.0L engine is a very reliable workhorse, but
also a 30+ year old design on which they slapped a new, fuel injected
intake. The usual array of sensors and sophisticated electronic control
already makes it as good as it gets; the gadgets you mentioned are snake
oil. I can only think of one trick: if like mine, yours came with the
'towing option' 3.73 (or even 4.10) rear drive ratio and you are not using
it to pull heavy boats out of the water, modifying it to a more modest ratio
will let the engine run at lower rpm when cruising in OD and save gas. Not
sure how much, but certainly will. But if you really want to save gas, get a
used econobox for the daily commute and save the Explorer for fishing trips.

Incidentally, if the numbers you are quoting are off the message center,
take them with a grain of salt. Mine are consistently 6-8 % more optimistic
than reality (actual miles/actual fuel consumption).