I am overall pleased with my used 2007 6.7L 3500 Dually that I got a couple years ago. Sometimes I wish it would upshift faster since it really seems to pick up speed just idling in top gear. However that is not my question today.

I wasn't planning to get a tuner or performance module for my truck, however I saw an ad for the Stealth Performance Module saying all kinds of good things (fuel economy stands out since I am getting 15mpg when I do not tow, 11mpg when I tow a 35' goose w/ tractor), but I wonder what folks have experienced with this (or other) tuners. I have heard about Banks Tuners, but they don't make one for my truck.

So, anyone know of a tuner that improves mileage without increasing wear on the engine? Thanks