I have a work friend that constantly complains that his fuel economy isn't what he expects in his hybrid toyota. It has taken me long time to get through to him

I have a work friend that constantly complains that his fuel economy isn't what he expects in his hybrid toyota. It has taken me long time to get through to him that fuel economy varies based on activities and environment... (cold weather/running the heater/mountain driving/towing items etc) I don't know why but he seems to be outraged that something as simple as running the heater in the car in winter will alter the fuel economy of the car.