I think the "real" advantage in terms of mileage is going to vary for each person based on a number of factors that have been discussed on here numerous times and i won't bother listing them again. On average i imagine the normal Camry would get 24-28mpg for the
4 cyl model, that is. In the TCH my average is hovering around 38-42mpg for the year that i have owned it using no extreme hypermiling techniques.