Note also that the Camry and Altima have identical "estimates", so Altima owners shouldn't feel like second class hybriders. Further, the car manufacturers are not the ones saying the car will get that mileage. It's a mandated test from the fed. govt. This is not to say the car manufacturers don't use this data as selling points, because they do. Shamelessly.

A NiMH battery will increase in capacity for the first 5-10 charge cycles (if you charge it up fully). It will probably take a few more partial cycles. Whether this will result in improving fuel economy I can't say, but I don't really see how, as the computer runs the battery from 40% to 80% full charge, so it shouldn't see the increase in capacity. Perhaps internal resistance also drops, and that would result in improved mileage.

Pearl is a
2007 Driftwood Pearl Prius
Package "B" (everything but leather, nav, and rear camera)