God point about the battery charge. I know for sure the hybrids lose efficiency in the colder weather. After warm up, they're fine. I've used two different Prius models for a week or so a piece, and we have the Camry Hybrid as well. The mileage I get from either has always been spot on. I'm sure there could be some inconsistencies amongst the same models, but certainly not dramatic ones. Virtually every tester of the new Fusion hybrid has achieved the same range of results. Most said getting to 40 mpg is unbelievably difficult. 15% is a lot of discrepancy. I think it's the 47 combined rating that is the most suspect. While the new setup is fantastic in that the electric motor can go up to 62 mph without assist, you'd have to do that in a rmeote location, since it takes a long time to get there.I think the 47/47/47 was a marketing success.