Drafting is for rich rednecks who only know how to turn left. Driving right up somebody's butt shows limited intelligence.
I prefer the term slipstreaming.
It is the science of placing your car in the proper wake area of the vehicle ahead conscidering wind, traffic, road conditions and vehicle speed in relation to safety. It need not be dangerous or irritating to either the lead or following vehicle's occupants.
Having an older car, that is not as sealed up as new cars, I have noticed a dramatic reduction in wind noise while slipstreaming. How can that not help your economy. You don't have to get all that close to see the benefits. All you have to do is get your car into the turbulent flow.