right now i have the 98 12v and am looking to add a new 6.7 to the driveway but i am wondering if there is much i can do to get the mileage up on the 6.7 with diesel being $3.13 a gallon here in NC. my 98 gets 18-21 mpg and im hearing reports of 14-17 mpg for the new 6.7 and upwords of 20 with s few delets they have inspections here in NC so the truck has to stay legal with emissions or be a fast fix so it will pass any help would be greatly appreciated other wise i might have to go back to the gasser which i really hate to do i love my diesel.

 

My 2010 gets 19MPG 68MPH on the freeway avg 1000 mile road trip to Wyoming from Seattle.

I get 14 maybe 15 with mixed town/country road driving.

You can do a programmer with "stealth" delete's, but you would still have to install the DPF for your inspections.

Many 2011's are reporting around 14MPG. Don't know if they got a new flash, or what the deal is...

 

Id look for an 07 5.9

 

Or get another 12V and have two