Fuel consumption on the Zuke and Liberty should be close at WFO if they are close in horsepower. The reports would indicate that the horsepower is indeed close. However the same horsepower in a lighter sled will have an advantage in this regard. Also fuel management at the lower rpm ranges will play a role in fuel mileage as well. Etec is the real benefactor of that part of it.
Mountaincat 800, after I referred to previous posts, the 2016 can weighs 17 pounds. Some of the weight loss is accounted for, ie, new track -4lbs, new rails -3lbs, new a arms/front suspension 3.2lbs. The whole cowl, tub and other parts are more compact than the Pro Ride and may account for some additional weight loss. Pro Ride was claimed 417 dry, Axys Pro is claimed 408 dry, difference of 9 pounds. Can difference is 8 pounds. Total of 17 pounds chassis/body difference. I have accounted for over 10 pounds of that leaving 6.8 pounds somewhere in the mix. That is the full extent of what I know, take it as you will. I think if you talk to that rep again, you might see if he said or meant 17 instead of 7.