I have a 2002 Quad 4WD with the 4.7. Truck has 188,000 miles on it. According to the onboard computer I am getting about 12.1 miles to the gallon. Last tune up with plug change was at about 160,000 miles. Where or what should I look for to improve the mileage? Even a few more would be great

 

the 4.7 was supposed to be better on gas mileage than the old 318s were.... most that I know who have had 4.7s say that in reality they aren't.
my 93 club cab with a 318 (5.2) and a 5 speed manual (that I transplanted in) rarely got less than 18 and on a road trip holding 70-ish MPH would routinely do 21+. had 3.55 gears and 225/70R15 tires. wrecked with only 204Kmiles, otherwise had NO intention of getting rid of.

my current 92, also a 318 club cab but still has its original A518/46RH auto trans gets a little less, usually around 17- 17-1/2, no matter how or where Idrive it. I know of a couple things it needs that is probably holding the MPG back a bit. also 3.55 gears and the same tires that I took off of my 93 after its wreck.... 92 is currently at 194K miles, bought with 167K.

I also currently have a 96 club cab with a 318 this one is a 4X4 with a 46RE trans... most recent buy. bought with 165K and trans/T case in bed, I rebuilt trans myself along with a mild shift kit (TF-OD jr) and a freshly remanned T converter currently at 170K miles. wife's current daily. Constantly improving in MPG the longer I own it, this one has 235/75R15 with 3.91 gears. still around 15-ish MPG, got to do the intake plenum and valve guide seals, (have parts already just have not had the time) after which I expect it to improve to around 17-ish in mixed driving. as long as there are 318s (and 360s) out there to buy, you wont see me in a 4.7 equipped truck.
the older engines were much simpler, less moving parts, less headaches to be had. I belive in K.I.S.S principle.

your truck being a Quad cab is heavier than mine which don't help in the MPG dep't. what gear? Stock sized tires? What driving conditions?
I know a guy (and have heard of others doing this mod) who put a Grand cherokee computer into his Durango which adjusted the trans shift schedule which he says helped his in th MPG department.... not really up on that gen of trucks.... I do have a 01 Durango but I have the "other" engine in mine= 360/5.9) and my mileage is slightly better than you claim out of your 4.7, especially on the highway.

 

Stop watching the display up top as it's very unreliable. Use the fill up method and do the math.

I get roughly 15 mpg in heavy Atl traffic. I've never done a long trip while not towing something, so I can't say what I get for highway mileage.

 

Reset the dang thing every time you get gas. Turn the display to show outside temp. Or OFF.

 

There's lots of things you can do. First of all, do the simple, cheapest things such as making sure the tires are inflated correctly. You'd be surprised how many people overlook that. IMHO, 4WD trucks never have gotten very good gas mileage no matter what you do. Keep clean oil in the engine. Dirty stuff can cause friction plus wear out the engine sooner. Change the air filter regularly. If the engine is starving for air, your MPG won't be very good. Make sure the steering is properly aligned. Most of this stuff is just common sense stuff.

 

I get about 16ish mpg give or take in my 2001, quad, awd, 4.7. 12.1 seems pretty far off... what kind of driving do you do??? IS this mostly city, hwy, hills??

Do what others have said. Check your air filter, tires, are any brakes dragging... Use simple math at the pump, not the computer (even though I have never had a problem with it).

After that; have the compression tested, leak down test also... see what shape the rings are in.

 

This thread is kinda pointless. OP doesn't know what gas mileage he is actually getting.

 

Beyond the honest comment about WTF do you expect, I will add the obvious. As was pointed out by others, do the actual math, don't rely on the silly display. Make sure your tire pressures are good, I like 35PSI maybe a few more. Do the old stupid but useful things like avoiding the proverbial "jackrabbit" starts. You yourself might lose 30 pounds (don't laugh!) Dump all the extra crap you may be carrying "just in case". Stay at slower speeds. Anticipate red lights and traffic flow. And what exactly are you trying to accomplish? My '01 has a 3.9, is a 4X4, and automatic. It is a Sport meaning it has a 3.91 rear resulting in lower MPG. My best has been 17 in 73K of all sorts of driving conditions. You will never win the Mobil Economy Run (if anyone here even knows what that was!). I know from speaking to GM owners that they got better MPG than I did with similar vehicles, although they were the small SUV and not the truck. I didn't buy mine for its fuel efficiency, that's for certain!

 

yea, if that truck is not idling smoothly, or you smell exhaust/carbon out your exhaust , you may need plugs (stick with Champion) , check plug wiring.
Run a can of Seafoam thru your next 3/4 tank of gas.,, that and other things mentioned. I get about 16-18 mpg driving conservative .
(i don't have the fancy computer estimate) .

 

Truck runs great. Tires at at 45lbs and checked bi-weekly. No codes. Brakes are great and when you take your foot of the gas it will roll and roll and roll down the road. Drive train is in tip top shape. K7N air cleaner is cleaned and not much oil. Washed and waxed to avoid drag. Tailgate is up and bed of truck is covered. No jack rabbit starts. Drive at speed limit. Most drive city driving. Usually one person in truck and nothing in bed. Have full tank now and will do the math and report back. WTF does anyone else need to know?