7-10mpg, yikes.. good thing that it is a toy, not a daily driver!! Looks good, though!!
The vette gets better mileage. The 327 routinely gets between 14 and 16 mpg combined when one doesn't play too hard. The riviera with the 401 averages between 7 and 10 mpg.
I did take the riviera on a 3400 mile road trip last summer (San Antonio to California to Detroit (and across to my home in Northridge, Ontario, Canada). I kept a full gas can in the trunk. 23 fill-ups.
In the fall, I took the vette for a 1900 mile cruise from Canada down to Texas.