That does seem low, my 2010 4x4 crew with 21k has averaged 16.1 mpg all hand calculated...I need to keep track of miles/cost for work. I do 70% highway 30% city... hills will take something away from the mpg as these are pretty heavy.

 

Yeah, you are a tad low from what I'm seeing among most MDS equipped Hemi trucks. I get about what you get and don't have MDS, not to mention weigh in just a hair under 7000 lbs. and ride on 35" tires.

As oldjeep has stated, messing with mods for improved MPGs is usually a no-win situation as just about all mpg mods cost way more than the slight improvement you'd get. It would take you a decade to make back the investment. The ONLY mod I did that made a noticeable difference and "paid off" as far as making my money back relatively quickly was my e-fan (and I'm still only talking about a 1-1.5 mpg gain, here).

But I think you need to address why you are getting 3-4 mpgs under what most 4th Gen owners are getting. Whether it be mechanical, driving habits or whatever. What are you running your tire pressure at? Low pressure by as little as 10 psi can result in a good 2-3 mpg losses alone.

 

What do you have on your truck to make it weigh that much?! I only see diesels up in the 7-8k range.

 

Lift (and let's remember when you put a suspension lift on an IFS truck it has a sub-frame),bigger tires, grill guard, a 65lb winch mount, a 115lb winch and a toolbox with prolly 350 lbs or more of tools, recovery equipment & a gas welding setup in there.
Not to mention when I got on the scale at the cotton gin, I was still sitting in there and I'm close to 280#. I weighed in right at 6985#.

I actually weighed it because Marty at KRC Performance and I were guessing at what the pig weighed. I guessed 6200lbs., he insisted it was gonna be every bit of 7000lbs. He was closer...

 

That's a lot of weight and drag for a gas truck to be pulling around.. Especially for long commutes like what myself and luckydt have to do. We both have to drive anywhere between 25 and 30 miles each way to work. And seeing as he gets some horrible gas mileage I had to reconsider getting a 6" lift and 35" tires.

 

im running 45psi in the front and 37psi in the back. i dont expect huge gains from mods i was hoping 1 mpg from an exhaust i really would aslo just like to know i have a hemi sense the mpg reflects that i do. i do understand that i have a big truck with a hemi i just hear every one getting better mpg that me with the hemi. hell i was reading a review on pickuptrucks.com that was geting 15mpg with a 3/4 ton hemi with 4.10 rear end and in getting 13.2mpg.

 

as for the oil change i know that synthetic doesn't mean better mpg just added protection i was just referring to havening new clean oil in the truck and it didn't seem to help from the initial break-in oil from the factory.

 

Am I the only one here that is thinking," Hmm, I didn't buy a truck for gas mileage. I bought it to use as a TRUCK."?

Honestly, I'm willing to bet that your problem is how you're driving.

I see people all the time (especially those who use their right foot for gas and their left foot for the brakes) complaining about their poor gas mileage.

If you ride with them or follow them, they are usually riding with one foot on the brake all the time.

More commonly, you'll see people who accelerate then coast, accelerate then coast, accelerate then coast.... That kills your MPGs quicker than if you were doing WOT runs in it. Steady and slow movements in the acceleration will do wonders.

 

Lot of people bought it for both. Big reason I bought the Ram was the 21MPG rating in the biggest motor they had, rather than having to get the little motor in the Ford or Chev.

 

well i hear ya on the people who drive with two feet or like the have a drag car but thats not the case i drive reserved no romping on the gas or riding the brakes i just want to know why im getting 2-3 mpg less than everyone else. and i know that i have a truce and not a prius but 13mpg is low i see guys towing that get that good.