I am looking into possibly buying a lmm dually and was wondering what kind of mileage you guys are getting running 19.5s? And how much difference the dpf delete makes when running 19.5s?

No idea on tire size but with stock tires one gets maybe 1 to 2 mpg better mileage. But my experience is closer to 1mpg better over stock with DPF. So my guess same applies with all tires if diff gears are changed to bring drivetrain back closer to stock.

Brian

19.5s are heavy and taller. You will definitely want to drop the DPF if you go with those. The taller, heavier wheel assemblies will "load" the motor more. This will generate more soot / which will make for more regens. Also, if you pull anything, the added soot will sometimes put the truck into a light "limp" mode where the DPF can't burn off soot fast enough.

Thus, you'll be hurting mileage by 1 or 2, as mentioned. Dropping the DPF and running the Quadzilla, I have noticed 2.1 increase in MPG across the board. Towing included.

It takes around 40hp and 40ft lbs to run the DPF/DOC system. That's probably about what those wheels/tires will pull also.

I average between 14 and 15 mpg running around with my 19.5's and dpf delete with the edge racing, mileage was similar with the quad but egts are much better with the edge.

I average 9mpg pulling the gooseneck and 06 Dodge to TS the other weekend.

Thanks RPA thats what I wanted to know.