One of your trucks clearly has something wrong with it. As does mine and apparently others too. I hope someone posts something other than "don't worry, be happy." I want my 24 mpg back!

 

19.2 w/ 150s, hmmmmmm I would call BS on a 19 yr old telling me anything let alone there are 150s in the truck. Did he give you receipts? Hopefully I'm wrong, I'm good at being wrong. If this is truely the case get a good set of matched 50s or 90s and your milage should skyrocket. Does the truck smoke before turbo spool, if so how much?

 

I have yet to have anyone prove to me they get 24mpg with their Common Rail. I've heard the talk for years, and yet know one can prove it to me. When I show up to go for a road trip, or a hunten trip, guess what....their 24mpg truck gets 15 or 16mpg when its comes time to fill it up. Maybe a 2wd lowered 3.73 6 speed with street tires at 50mph gets 24mpg, but our real trucks and real conditions.....no way. Show me. I'll even pay for your fuel. I'll meet ya half way.

 

Getting 19average. Wife drove truck to Iowa and got 19.8 , I drove the truck to north Carolina and got .19.1. But between city and highway I average around 19 w/truck in signature.

 

I have a similar story.... Truck just didn't feel right. I attributed it to the low sulfur fuel and didn't think much of it. Truck idled fine, started fine and showed no symptoms of being ill. Well a friend of mine works at a Dodge dealer and told me to come down with the truck and he will hook up his scan tool to it and see what is going on. We found out that the fuel pressure on the high side (after the cp3 pump) wasn't high enough. After more investigating and luckily I was still under warranty, the cp3 pump was replaced and the high pressure relief valve was faulty and replaced also.

Now with all that replaced, I got 20.3 mpg, all highway, travelling 65 mph. That is the best milage I have ever gotten with this vehicle.

 

My 03, 2WD with street tires. was getting 20 plus all the time. Those days are long gone with the arrival of the HO cummins, 4X4 and big tires.
Thank god work supplies me with fuel.

 

No, not for a 2003, 4WD notwithstanding. Should be at 22+ at 60 mph, perhaps better. It's down at least 10 -12%. I agree with MikeyB. The tires, however, need to be stock also (MICHELIN LTX A/S is a "green" low rolling resistance tire). Come closer to that as well as tip change. The other add-ons (exhaust, air intake, tuner, etc) are worth nothing in re steady state highway mpg.

 

I can get almost 21 if driving no faster than 56-58 mph and using Bulldog set on CL.

 

I netted 20.4 and 20 mpg for my last two tanks. Mix of stop and go and highway.

MikeyB

 

The closer to sea level the better the fuel mileage

 

I now have a set of stock wheels on it and a set of wrangler 265/70/17's. I drive the truck real conservitive as I have stated before.

so I have

afe stage 2 cold air kit with lid
mbrp stainless exhaust 4 inch
150 horse injectors with the receipt and flow numbers
bullydog E3 economy box with the economy tune in the truck
3.73 gears
it struggles to get 17.2 now.

I am very dissapointed.


With the economy tune in the truck it barely smokes, when you put it to the stock tune it smokes a little, but not like I thought it would.

 

Are you sure the speedometer is set correctly? Maybe the ECM had been updated at some point for different tire size?

 

The speedometer reads right on with the GPS unit.


This week we drove it with the box set to "stock no power added" and it got 17.62 mpg.

With it in the power added tow hual economy mode the truck got 17.2, but it had a lot better throttle response and just all round driving was better.

 

I can get 24 mpg with 34" tires.... Heck I can get 25.5 on one stretch I run that is 40 miles of small hills and only one stop sign..... But I have to drive like an old lady.

Normal driving will net me 18 mpg with the Smarty set on 100hp and cruising at 74mph. It's the hills that kill me. And the fuel. When I go south my mileage ALWAYS goes up. I think the fuel is better than here in Wisconsin!

 

Should I get a different box for it to see if it will help?
Since it is has the 150 hp injectors in it what should I do to utilize them?
I see where a lot of people like the smarty box, but I dont want to install guages in the truck.

I got a buddy telling me to keep the box I have, put a intake elbow on it and a boost fooler to get more air to it.