Sythetic oil got me 40mpg

[roxy1]

in my experience, winter gas formulation hurts mpg considerably more than colder air. I will see a 10% hit at any given temperature with winter vs summer gas. many parts of the country start with winter gas around early October.

still, even with winter gas I am getting 43.4 mpg (actual calculation) per tank on a mostly light suburban and 15% city commute.