'15 Sierra - What's your highway MPG?
Let me know what your averaging in a 2015 4WD crew cab 5.3 and 6.2 on the highway only. Don't really care about city mileage. Make these realistic - you know, driving down the interstate at 70, 75, and 80 mph.
I have a new 2015 5.3 4WD Denali. Getting...