[Dcarver]

I was just wondering how much of an increase I can see with a scangauge in terms of mpg with my 5.7 Chevy Tahoe? I use this as my DD because of the space it allows for my family and the ability to tow 6k lbs. I also couldn't afford a decent diesel. Anyway I'm averaging about 16mpg combined and its tuned up properly, tires inflated to max sidewall, I do my very best to not go over 55mph when on the freeway and coast as much as possible up to stop lights so I won't have to stop completely.
I know this thing is a brick and the engine isn't ideal but its what I got and I guess it can challenge the best Eco driver so please any tips on increasing the combined mpg to 18 or better would be appreciated.
Also, reverting back to my original question, will a scangauge help me specifically?
Thanks