winter gas just sucks. also i was running the autolites in my 05 4.7 and noticed that i lost 45/50 miles on a tank of gas. went back to the stock champions and mileage went back up. my 97 fullsize 5.2 got great mileage on the ave. a little over 400 miles on 26 gallons. i did mostly highway driving 70 miles a day but even in stop and go it was good. i had one of those open air elements and it cost me. for some reason i would get a back fire into the tb. switched back to the stock tube and it went away.

 

considering you have the heavier 4x4 automatic, with the 360, i'd say you're pretty close to average, even a little better than most. anything you do to the motor to make it more fuel efficent is generally only going to yield a couple tenths of a mpg, if that. a better way would be to shed some weight, as the truck is damn heavy. lose anything unnecessary you carry with you. having the aerodynamics of a brick doesnt help these trucks either.

in all honesty if i were you i wouldnt expect a huge gain from more mods, maybe another 0.5 mpg, if that. it would certainly be cheaper in the long run to purchase a smaller more fuel efficent vehicle to use every day.


but look on the bright side...i'd probably getting like 6 mpg right now. at least youre doing a little better than that

 

LOL... that sure puts it in perspective! I was just wondering because a couple years ago I had another 97 optioned the exact same way. That truck brought me 15mpg all day. Looks like the ole Honda will be my daily driver to and from work

 

i also here that royal purple is very good i havent used it in my truck but my friends do they say its worth the extra money. Also i would reccomend the circle filter i am running one of those and i find it much better then the k and n fipk

 

When an engine is new and fits are still tight at the piston rings
a low viscosity oil can reduce friction.
There are independent dyno tests of this
like this one by Marlin Davis:

http://web.archive.org/web/200211132...e.jsp?id=15378

Synthetics have also been independently found to have long lifes too:

http://neptune.spacebears.com/cars/stories/mobil1.html

However, when an engine gets old
like past 125,000 miles
a heavier grade oil like 15W-50 from Mobil One
can improve the 'nearly worn out' ring seal
and give better MPG, and perhaps slightly less blow by gases.

from the FAQ:

LUBRICANT, EXHAUST & DRIVETRAIN MODS

Switching to synthetic lubricants - - engine oil, diff, synthetic Mopar-spec
transmission fluid, and syn greases in wheel bearings is good for 2-5% MPG
improvement. That is only about 0.5 mpg but every little bit helps.

In the Cummins 'Physics of MPG' white paper they recommend synthetic
lubricants in transmissions & differentials but state that conventional
oils changed often are the best cost compromise in the engine.

Larry Shepard writes in the 'Magnum Engines, 1st Ed' book published by
Mopar Performance that running engine oil and transmission ATF levels
1-0.5 quarts below the 'add' marks on the dipsticks can increase MPG slightly
due to less oil drag. If you do this, you must check levels very frequently
to see that you don't drop oil levels even lower into the 'danger zone' and
some experts on 46/47 overdrive automatic transmissions advise the oiling
passages to the OD unit need to be enlarged for more ATF flow in any case.

Recently there was a post from a Chrysler employee working in their dyno
testing department saying that running a 5.7 Hemi Durango one quart low
(6 quarts instead of 7) on engine oil would give about 3 hp gain at wide
open throttle and high rpm. This supports Larry Shepard's advice but
also confirms any gains are small.

Further support that oil windage can affect hp and torque as low as 3000
rpm on a 350 ci engine filled from 4 quarts to 8 quarts is found in this
carefully done Circle Track magazine article's dyno tests, but the MPG
effect in the 1500-2500 rpm range would be small:

http://circletrack.com/techarticles/...age/index.html