I'm looking at about 3 hrs to fill my Subi. I'm buying about 1 1/2 tanks a month.
So, about 4 1/2 hrs a month to feed my car engine.
A case of Clif Bloks costs me a bit less than 1 hr. When I'm biking a lot I go through about 2 cases of Bloks a month.
So, about 2 hrs a month to feed my bike engine.
Hmmmm... bike wins! 
(does this mean I can buy some more bikes? Like, oh, say a recumbent tandem and an Xtra-cycle and a mixte and a pedicab and...)
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson