I've kept up with every gallon I've burned in this truck and keep the data in a spread sheet. I get in the 10-13 range because most of my miles are pulling a 5th wheel trailer. The non-towing miles are in town and I get around 15 mpg.
I use this one, too. I like it because I can preprogram my destinations using the coordinates entry in the "where do you want to go" section. I find that all of them have data bases that don't have all the addresses I want, or businesses like campgrounds don't advertise gps-friendly addresses...
Armor All is sticky and attracts dust. After a day or so, the tires look really dusty and dirty just sitting in the driveway. Also, I just don't like the look of the "slick" tires.
I use a long handle brush and a good name brand car wash liquid. I dry it by hand because the water is very hard here. I don't use ArmorAll or anything else on my tires. About once a year I wax the top and the hood.