WOW SD26, that is one impressive spread sheet. thank you for sharing. those numbers are very helpful and a bit disappointing at the same time but at least it is realistic. thank you
LOL! Yeah, life sucks, eh? Yes, I nearly hit 19MPG a few times. My life time MPG includes towing a big trailer and a small trailer. Does have an impact in the overall average. As does winter in Wisconsin. 13-14MPG in the cold seems to be pretty regular for me. Definitely is in the 16-17MPG range in the summer. My regular work commute is about 24 miles, so I get good and warm. It's not interstate driving; it's rural, mostly, has about ten stop signs, and takes me 35 minutes plus to do. So, I wouldn't call my MPG highway. That kind of helps, right?
As for the spread sheet, fuelly.com is free. I just like to load it up with data. One has to read it carefully as what goes in the tank might reflect on the next MPG and my driving notes are based upon the previous data's fill.
I don't think my DP Tuner necessarily netted any kind of a real gain in MPG. I would like to go to a narrower tire, maybe a 255/85 or a stock 265/75...or maybe even a 235/85...but that's a cost that I don't want to incur right now. The big 285's look good and have a lot of tread left. Might make a simple air dam for the front. Doubt I will get a big gain on my regular commute, but maybe a little more on long trips.
What kind of MPG are you hoping for? The Excursion is heavy. I think that hurts it, but it is such a comfortable vehicle. There is a real value in having it for it's great towing ability, comfort in people hauling, and general utility. The DP Tuner makes it just that much more fun to drive also.