The carbon in the exhaust is measured to calculate the amount of fuel burned during the test. This is more accurate than using calculations based on distance traveled and the amount of fuel consumed. Five separate test schedules are driven to simulate the driving conditions of city, highway, ...
You could perhaps organise a meeting to test drive a car at a dealership (chances to nick rare or even dealership unique cars) and select positive, negative, neutral or something else answers to friends questions, which affects there respect or like of you.Now I know these things sound crazy...