srg963

2015 SCrew with 5.0, 3.73, 4.5" lift, 34.6" tall tires...averaging 15.768mpg, and I don't baby it lol

Should increase a bit after a lighter wheel upgrade.

GreenScrew

Stock '16 Platinum with 36 gallon tank, 3.55, and 8K miles. I routinely get 19-22 mpg on 2 lane highway posted 55 running between 59-62. This is based on a weekly trip to the weekend cottage that is 120 miles, and using cruise pretty much the entire way and typically a few full throttle passes. 3-5 stops along the route. I always fill the tank before making the trip.

That said, wind alone can have a decent impact on mileage between 2-3 mpg.
Running at 70 or faster on long freeway drives has a bad impact on mileage bringing it down to 16-17 range.
Pulling a loaded 2-place snowmobile trailer and running at 70+ freeway speeds I can easily get 9-13 mpg. And that's on long stretch with no stops based on computed fuel mileage history.

So, LOTS of variability. My personal experience.

SloMoJoe

I'm not a platinum guy, but I'll chime in on the turbo issue...


I drive a 3.5L Ecoboost with the 3.31 gear ratio. From my observations, dropping from 6th to 5th gear = about a 2 lb. drop in boost on my truck at highway speeds. So, the 3.31's do use more boost, because they need to use the boost to make up for the lower torque which is the result of running lower RPM's.


All the following observations assume that the cruise is set at highway speeds, which for me is 77 mph:


If memory serves, my 3.31 runs about 15% fewer RPM's than my 3.55 did, which I believe means that running a 3.55 is the equivalent of running midway between 5th and 6th gear in a 3.31, and running 3.73's would be the rough RPM equivalent of 5th gear in a 3.31. This should mean that a 3.31 at highway speeds will average 1 lb. less boost than a 3.55, and 2 lbs. less boost than a 3.73.


That being said, I'm not sure what the tradeoff is between RPM's and boost, in regards to fuel efficiency. Is it better to run at 2 lbs. boost and 400 RPM's slower, or is it better to run at 0 lbs. boost and 400 RPM's higher? My calculations say that it's about a wash.


This time of year, I'd be pretty disappointed if I got less than 20 mpg with the cruise set at 77 mph on a road trip of 100 + miles. But I drive in the Midwest... It's fairly flat. For city miles, I'm not so impressed with the 3.31.

iFord

Thanks boys, y'all have come through for me! I want to test drive this one again before I decide, but now I'm leaning heavy toward getting this one. One reason I want at least a Lariat and above is I suffer with daily pain, fibromyalgia, etc., and it's amazing how much the little things like auto running boards, seat and steering wheel moving out of your way, things like, mean to me. Needing a neck fusion as I write. So, the Platinum level is really more of a necessity for people like me. Plus, that sounds good, right? Just jesting, I do need all the help I can get in pain relief department in my daily life.