My normal route over the mountain is a rual 4 lane divided highway with somewhat limited access. Speed limit is 55, and there's no sharp corners. Going down I shift to L and let the battery regen until full. Once the pack is full, the FEH DFCO's the rest of the way down.
The first generation (2004-2006) Scion xA and xB share identical drivetrains (engines, transmissions, axle widths, final drive ratios), and they weigh essentially the same. The xA has a cD of .31 and is .3" narrower and 4" shorter for a cDA of 7.00 v. the xB's cD of .35 and cDA of 8.46. The EPA estimates C/H/Co of 27/34/30 for the xA, and 26/30/28 for the xB.