I would like to know if many hybrid car owners drive on highways or urban expressways that allow them to drive at 55 mph or higher, and what sort to total mileage they get. Do people actually calculate their average mileage by zeroing out the tripmeter when they fill gasoline and then next time divide the total miles travelled by the amount of gas they fill to note the average mpg? Do people bother to estimate their total yearly expense on fuel, or is the feeling of driving a more ecofriendly vehicle the more important criteria for deciding to drive a hybrid? Looking forward to getting some feedback.