Has anyone modified their 6.7 yet with fuel tuner and exhaust? I am thinking about a H&S Tuner and some sort of aftermarket exhaust. Just wondering what type of fuel mileage increase I should expect. I have about 6,000 miles on it now and am getting about 14.5 around town and up to 17 on an extended trip.

 

plenty have. go on cumminsforum.com you will find everything you ever wanted to know about dodge cummins motors on there. it gets 100x more traffic than dodgeforum does making it a super active site.

quick answer to your question, if you don't care about your warranty, get yourself some gauges, throw a 5" mbrp straight pipe on there, and EFILive tuning. that will give you the most power, and best fuel economy from what I know. I'm not a 6.7 expert, I just know from what I've read that deleting the DPF and EGR gives a good economy boost, and EFILive is the greatest tuning since the smarty tuner on all common rail trucks.(5.9 and 6.7)

 

There is no EFILive for the 10+ trucks. Best bet is probably H&S Minimaxx, 5" turbo back exhaust, delete the EGR cooler. You can get everything from H&S.

You can get upwards of 20mpg +/- on the highway, depending on numerous factors of course