Very excited about this news! I just hope that it includes the 2500 level as well. The way this is worded it sounds like it may only be an engine option in the 4500 series which may fall under different CAFE requirements thus allowing the thirstier engine. Ford does this with their medium duty trucks by still offering the 6.8L V10 gas which isn't available in 3/4 & 1 ton trucks. I for one would love to be able to replace my '05 Ram 2500 5.7 Hemi with a new 2500 6.4. The 5.7 is great but does run out of steam when I hook my tandem axle equipment trailer with Farmall 400 tractor on top to go to tractor pulls. I want more power but can't spend the extra $8,000 to $9,000 for the diesel option. I also realize that a 3/4 ton 4x4 truck will not get good gas mileage, so I don't worry about that. I just want good pulling power at a reasonable cost.