I am not sure how this topic ever came up, but it did over a dinner some friends and I were sharing. One friend told a story a woman told him. She had told him that she, in her VW Beetle, was able to get behind an 18 wheeler, shift her car into neutral and then draft if for an extremely long period of time, to the order of about 50 miles or so.
I argued them and said that it was not true and couldn’t happen. I tried to explain what I believed, that what would happen would be an extreme decrease in resistance for the car and that a vehicle would be able to travel at the same velocity with a greatly decreased need for energy [ie. pressure to the gas pedal] or that it would be able to travel further than without an object in front bearing the majority of wind resistance. (But even if it were possible in a frictionless, perfectly flat environment there’s still those factors that would never allow it to happen, right?)
They however argued that the wind would create some sort of force to essentially hold the car behind the truck and essentially tow it along. One argued that a system of high pressure and low pressure air could create essentially a force to maintain the car’s velocity.
After trying unsuccessfully trying to find a good answer to support either side, and the mass majority not agreeing with my position, I had to ask.
Which is it?
Can anyone please explain this as in depth as possible?