I don't believe in the whole location thing as much. I live in NJ and these are far from flat lands out here. Learning to be a little bit patient and anticipating traffic plays a much bigger role in increased mpg.

I have tried different experiments on my daily commute of 43 miles to work doing about 70% freeway driving and the rest on 29% large streets (Route 1 South) and very few minor arteries (less than 1%).
These are the results:


I obtain approximately 35 mpg when I drive @ a speed of 90mph on the freeway and complete the trip in 51 minutes.

I obtain approximately 39 mpg when I drive @ 80 mph on the freeway and complete the trip in 55minutes.

However, when I drive at 60mph (actually varying my speed between 60 to 80 mph based on varying elevations) I complete the trip in 1 hour and obtain over 43mpg, sometimes as high as 49mpg.

Patience plays a bigger role.