I've been thinking about "balance" a lot and both sides have good points. If you go too far to the negitive, no one is going to want to buy a hybrid in the first place (not good) and if you go too far the other way by being overly positive, people are going to be disapointed (not good). It seems to me that balance is the key. I think everytime EPA numbers are published or hypermiler numbers are quoted a huge disclaimer should be issued. A list of things that negitively impact mileage should be included in the disclaimer.

Example:

HCH EPA 46/51 mpg with some getting over 60mpg. Your mileage will vary and will likely be lower. Cold weather, traffic, stop and go driving, hilly roads, warm ups, low tire pressure, hard acceleration, and fast driving tend to lower your mileage. Please use EPA figures for comparison to other cars only as they do not reflect typical results. See the "greenhybird" mileage database for real world figures.