Since it was your wife driving, her foot probably isn't as heavy as yours, especially from stop lights.
I can't help but trying to be the first one off the line from the lights or my mileage would be better
Well that's not really true lol, she pretty much puts it to the floor. When we test drove the truck she was burning rubber out of the dealership.....I don't know how, I can't seem to get the tires to break loose unless powerbraking haha. It was all highway so that couldn't be it. I've noticed from the very few and short highway driving I've done in the truck the evic always shows the instant mpg as around 22 or 24 sometimes depending on speed, this was just the first trip that was really measurable.