ok guys my 2002 fuel mileage sucks iv had different issues with it had a miss at idle changed injectors fixed miss put dap 50hp in it got a edge ez tuner fass pump boost gauge about 10 on it when getting in it and about 4-5 driving 55 fuel pressure 20lb idle 16 down highway iv checked fuel mileage in town about 13 mph . so could tuner or injector cause bad fuel mileage i mean shouldn't it get a little better i drive like a old man  thanks.

What gears do you have?  If 4:10's your not too bad.  How the go pedal is used makes a big difference.

 

L8tr

D

If you have 4.10s that sounds right. Driving easy on the skinny pedal is your best bet.

My truck  with 4:10's  gets 14-16 around town, 16-18 freeway and I am an old man. 

I just put in new RV275 injectors so we'll see if there is any improvement.

Edited April 14, 20187 yr by IBMobile

My best mileage so far is 19.4.  Obviously no highway. I typically average 18.  I would guesstimate almost 17 highway. I drive like a dead grandma...god rest her sole

 

L8tr

D

On 4/13/2018 at 6:43 PM, juspassinthrough said:

got a edge ez tuner

 

Need to ditch the tuner and jump up to a Quadzilla Adrenaline. The biggest thing you have ZERO control of the timing and very little if any control of the fuel. I'm able to touch 21 MPG with just the Quadzilla and no wiretap for one year. 

 

I know this is going off track a bit. Like my 1996 dodge 5.9L V8 I'm running 235/85 R16 tires on 3.55 gears this makes the final gear ratio about 3.43. Now after doing a bit of study work I'm going to change on this next set of tires from 235/85 R16 to 245/75 R16 which will drop my final gear ratio to 3.72 roughly. This will reduce the load on the engine. Now in your case you rear gears at 4.11 so what size tire are you running so I can find your final ratio.

moparman don't no axel ratio but at 65mph I'm turning 1800 and have 265-75-16 tires

you have 3.55's if you are at 1800 rpm at 65 mph.  

 

Biggest thing with the EZ canned tunes is you need to keep engine load sub %25.  Once you top that timing falls off from ~18-19* down to 12* and your MPG follows.  

 

A set of 7 x .010's will help you do 65 mph while keeping engine load down.