Any one have real world experience and mileage numbers to report?

Is their MDS on the 6.4?

and, how are the 6speed automatics, I can't grasp buying a automatic, but I want a truck equal to my hemi 6speed manual (minor mods) in power and towing ability, but, will get at least 18 to 21 mpg highway at 60 mph empty.

reg cab 4x4 , ie basic work truck.

first choice is GM 2500 with a 6.2 gas, CTD with a 6sp man is not worth the extra cost.

I have not test drove a 6.4 Hemi

 

Test drove one, researched the hell out of it but in the end, I just wanted a diesel. Hadn't owned a diesel since the mid '90s and I just wanted another one. Yes, it has MDS.

Have a co-worker buddy with a 6.2 and I've been in it many times. The Hemi pulls way harder but even with the new three link up front I think the Chevy rides a little better, undoubtedly the IFS. Both interiors are light years better than Ford.

I don't think you're gonna see 20 mpg with any gasser 3/4 ton. Most 6.4 owners I know report 16-17 unloaded on the highway BUT, I'm sure nobody is going 60 mph. The big difference is hauling/towing. I know a guy reports 17 mpg highway but down around 10-11 towing his camper (10,000 lbs.)

By comparison my Cummins is averaging just under 19 commuting to work hand calculated, havent taken any trips yet but my evic says 22-23 doing 70 on the interstate. Most guys pulling 10-12,000 lbs see 15-17 on the highway.

The 67rfe in the 6.4 seems to shift smoother than the 68rfe in my Cummins, but that's to be expected, the 68rfe is designed to handle 850+ lb/ft of torque...

 

I traded in a '11 silverado 3500 4x4 for '12 RAM3500. The 6.0 gasser Silverado best ever was 17.3 @ 65mph running on I-80 through Wyoming and Utah, some I-25 in Colorado. That truck was just too heavy (7000 empty) to do better. It did not have a "MDS" type system on it.