Like stated before you are dealing with the extra weight of the 3/4 ton, the only help would be synthetic oils, watch tire pressure closely, use a highway ribbed type tire/nothing of aggressive nature. Maybe a bed cover but it really won't help that much (.2mpg roughly), K&N drop-in air filter or better air intake kit, magnaflow exhaust, and light foot on the pedal.

The best I used to see on crusie controled trips doing 70-73mph in my 07' 2500 Hemi, 3.73 geared 4x4 truck was 17.3-17.5 mpg.

 

I appreciate all the replies!

I've put 1800 miles in the truck in 2.5 weeks. My last tank was my best tank at 12.6 MPG, calculated by hand. Thats approx 50% highway, 50% city. It seems that if I could do a full tank on the highway, I'd get pretty good mileage. Probably around 18-19. Its the stop and go traffic that kills it. I really drive with a light foot, as I have been trying to conserve fuel.

I'd like to get a little better mileage if I could in the city. I think if the truck pulled a little stronger off a light with less throttle input and lower RPM's, I'd save some fuel for sure. Having extra power to tow my jeep would be nice too.

I'm thinkin tuner first, the intake and exhaust.

Those things should help a bit, or hurt a lot!

Will the dealer give me grief about a tuner? Do I need to remove it before having the truck serviced? Superchips or Diablo?

 

I would think the dealer would give you a hassle if you left it in while it was in the shop. You can always remove the program and return it to stock when it needs to go in then reset it back afterwards.

My buddie did that with a Superchips tuner on his Powerstroke Diesel. After awhile the dealer caught out but had a hard time proving it. It was a lease and he beat the mess out of it. Big lift, big tires, maxed-out programer. After about the 3rd or 4th warranty issue they black listed his truck for warranty repair. He did a number on that poor truck, blown turbo seals, cracked head, etc. He never open up the intake & increased the exhaust size, everything was stock so he had way to much restriction for all the power the programmer was giving it. The dealership had to be able to figure it out if I could.

 

With 3.73 gears, that would be a good reason why your city mileage would be down. 4.10s would get you up into the powerband sooner and give you more rpms with less throttle.
Great performance mod, good mpg mod, but because of the cost, probably take you 50k miles or so to make it back...

 

Hammer,

I believe you are right. That makes the most sense.

A buddy of mine owns a 4x4 shop, so I can get the gears and install at a good price. I'm gonna call him later.

 

Vornado!

 

Mythbusters did not one but two episodes on this and disproved it. Tonneau covers do nothing for MPGs. They even used the Chrysler wind tunnel.