[Blue Bomber Man]

Weight is an issue with energy consumed with acceleration... but lets not forget the real issue with weight: Rolling resistance. force to rolling resistance is F_r = weight * rolling resistance coefficient of tires. I am sure that force to rolling resistance is much more of an issue for hypermilers than acceleration.

Acceleration is a loss for these reasons: Engine performs worse when struggling, and braking. Since we coast a lot to minimize that loss, we can attribute most of our loss of weight to rolling resistance. (and think about highway driving where we dont break at all if we are careful)

Serial hybrids have the potential to be far superior to a parallel hybrid. This is because the whole drive train can be more efficient, and the ability of the vehicle to run as all electric off the grid for shorter ranges.